Those making $1,000+/month on side projects – what did you make?

563 points by MucuMare ↗ HN
As it's a new year 2015, let's re-open this topic to see how things are going on this front :)

It can be a SaaS app, a mobile app, or any side project that is netting you recurring revenue

546 comments

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It's been a few years, but at one time I averaged $3,500.00 per month, with two months at $5,000.00, from two AdSense units on just one single, quite lengthy but well-researched and well-written essay on legal music downloading.

I am, today, skeptical that it's worth anyone's while to try to make money from ads published alongside one's articles. At one time that was widely accepted as the very best way to make money online, but no more.

I'm getting ready to do a KickStarter project so I can devote myself full time to this:

http://www.warplife.com/jobs/computer/

So far I have some remote employers and clients, and some employers in a few large US cities. After I have lots more remote employers, as well as some in a few other countries, I'll do the kickstarter.

Someone managed to make fifty-six grand from a KickStarter in which he said "I'm making potato salad". Not that he was going to sell it commercially, or had come up with a killer potato salad recipe. I mean like he was fixing his lunch for the day.

Just a couple days ago, I read that three times as much money is raised from crowdfunding than from VC.

Consider that with crowdfunding, you don't lose any equity. You also don't have the problem with a bad VC giving you bad advice, or even demanding you do stupid things.

There are some VCs who are very, very good. Despite having to fork over lots of equity, the good VCs are very worthwhile, but IMHO a bad VC is far worse than not getting funding at all.

Side projects usually enjoy a brief moment in the sun, and then start losing traffic (or in modern parlance - money). Any further effort to promote them is fruitless, because the chances are; the same people you are targeting have already seen your project. It's like when movie franchises (Dumb and Dumber for example) try and milk the format.

A golden rule I try to live by is try many different things. Try every single avenue you can. When one avenue burns out, go down another one.

I still write lots of articles and essays, but I don't focus on any one topic.

I'm not running ads anymore. Some of my articles still have affiliate ads for books, but I placed those ads years ago. My new material doesn't have any ads.

I figure that if my writing is well-received, something good is bound to happen to me. Other than my plan for the KickStarter - which I am not dead certain I will actually pursue - I don't have any specific plans for monetizing my site.

I always assumed you had to know how to make a compelling video to succeed at kickstarter. And as a correlate be charismatic and photogenic.
I ran a successful Kickstarter with what I believe to be a cruddy video. https://www.kickstarter.com/projects/1985705009/pimame

I think there are two spectrums to successful Kickstarter videos: Over the top really well done quality videos, and super low budget (read: $0) iMovie videos that show sincerity.

Anywhere in between that and you come off looking like a scam.

That is a good point. I helped with a kickstarter for a fusion project. Our budget was low but we hired some marketing people who spent about $6000 putting together a video for us. It wasn't great but it was the best we could manage. We got a ton of comments about how scammy we looked, including from many of the project's long-time supporters.

(Luckily it didn't hurt us too badly, we raised $180K.)

I have two close friends who are professional filmmakers, Sari Gennis and Ted Arabian. Sari was the animation director for Ferngully, her sister was my boss' girlfriend back in the day.

I met Ted in high school, when he and I both played Roman Soldiers in Jesus Christ Superstar.

However I plan to make most of the video myself, but then to have Ted edit it. Real Soon Now I'm going to make a storyboard from digital still shots, then an improvised voice track, then I'll transcribe the voice track into text and edit it down to where I think Ted could get it to fit into three minutes.

My plan is to produce a quality video but with some very humbling imagery. Consider that a homeless fellow here in Portland, not long ago said to me "Some of they people I find sleeping on the street, they tell me they used to make six figures".

I find lots of software engineers eating at soup kitchens and sleeping in homeless shelters.

It's not exactly like my computer employer index is going to find them jobs, but that if I can make it easier for most people to find jobs, then everyone will benefit.

    Consider that a homeless fellow here in Portland, not long ago said to me
    "Some of they people I find sleeping on the street, they tell me they used
    to make six figures".
    I find lots of software engineers eating at soup kitchens and sleeping in
    homeless shelters.
wait a minute, what?
Not surprised. I remember having a conversation with a homeless panhandling ex-software engineer in front of the NYC Tower Records store (original one on 4th & B'way) almost 30 years ago. He claimed to make over $500/day panhandling and, from his style, I believed it.

Yes. He really either used to be a programmer or was faking it extremely well!

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Realizing that personal anecdote is in no way data, but I've backed 49 Kickstarter projects and have never one watched a video.

Edit: Apparently I've backed 59 projects, 10 didn't reach their funding goal.

I'm in the same boat: I almost never watch the videos. However, I've also run a Kickstarter of my own and, while researching it, found that videos make a huge difference.

We're both HN posters, which puts us in a pretty small demographic. :)

> Just a couple days ago, I read that three times as much money is raised from crowdfunding than from VC.

Citation required. That doesn't sound possible.

I found the cite in an article by a VC, linked from HN.

I'll post it for you but not just now as it will take me a while to dig up my bookmark, also I need to get some sleep.

I'm skeptical too, but that's what the VC did claim.

According to Kickstarter's own metrics (and I'm sure we agree that they're the clear winner in this space), there's been a total of about $1.5B in funds raised TOTAL, over the lifetime of the site: https://www.kickstarter.com/help/stats

Conversely, there was nearly $30B in VC money committed in 2013 alone: http://www.pwc.com/us/en/press-releases/2014/annual-venture-...

So it's not even close to being close. Maybe there's 3x more crowdsourced projects funded than companies backed, but most KS projects are funded for a few thousand dollars.

I wrote a book[1] a year and a half ago that just recently crossed $42k in total revenue. These days it consistently earns $1.5k/mo without much further input from me, other than tweaks to the landing page copy and updates once in awhile when Stripe or Rails changes significantly.

[1]: https://www.masteringmodernpayments.com

Edit: If you'd like to read a preview, you can do so here: https://www.masteringmodernpayments.com/read

What proportion of that revenue are you receiving?
I use Stripe (and sometimes PayPal) so I get 97% of the gross revenue. Monthly recurring expenses are a cheap VPS to run the app and Facebook retargeting fees.
I was thinking about doing something similar. Do you recommend using your own domain name (like nathan barry) or having a custom domain?
If you have a domain name already, use it. I launched with just a page on my blog and later moved it over to a separate domain. I don't think it matters in the long run, and in the short run you get a boost from your personal domain that people already know.
Why not both? Make a custom domain for the book, then treat your own site as if you were guest-blogging on it to pump link juice to the custom domain.

That way, your venture ends up with the combined page-rank of your personal brand and the exact-domain bonus. (Whereas if you just redirect from one to the other, you lose one or the other.)

Hi, are you an expert or at least well established in the community? Because that usually helps a lot to sell. Thanks!
reddit.com/r/SideProject is a great place to look for such projects.
it's private
Doesn't seem to be, I just checked
You went to /r/sideprojects, not /r/sideproject
I started a little niche webshop in 2011. In 2014, the monthly revenue were around $2500/month.

It's not passive income, but I only use ~ 1 hour a day on it (packaging etc.)

Is there any potential for improvement? Like, devote more time to it and make more? 1 hour a day = 31 hours a month = $80/h, roughly put.
Sure! And I have big plans for 2015. Both being bigger in my home country, and expand to other countries with the same concept. In Q3 of 2015, I hope to have tripled the monthly revenue!
Time to team up with someone abroad... What's the niche about? :)
What is a "little niche webshop" if I may ask? What exactly do you do?
What is a "little niche webshop" if I may ask? What exactly do you do?
What is a "little niche webshop" if I may ask? What exactly do you do?
I left my full-time job back in February 2013 (coming up on 2 years). I currently split my time between consulting and growing my products (a downloadable and a SaaS). Revenue from my oldest app is still > $1000/month. Been a fun ride so far.
What's the downloadable, if it's not confidential?
A local community website, earning from local ads.
Would you mind sharing the population you reach?
Do you work with retailers directly for local ads or an adsense-type site? You do $1k/mo for this?
Would you mind sharing the URL? Thanks!
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Create a Job Board, use the latest social routes to drive traffic and build a list.

The amount you make from the Job Board post is heavily dependent on the amount social followers (drives traffic and makes purchasing more appealing).

https://www.angularjobs.com started making ~$1000/month in revenue with a highly targeted social reach of ~10k followers.

Technical co-founder type? Take what you know about programming and offer recruiting services to the early users of your site. Both companies and developers visit job boards, providing both the clients and talent needed to collect recruitment fees(over 10K in major US cities).

My main gig is http://www.LinkPlugApp.com where I play a technical role.

LinkPlug is how I drive traffic to the JobBoard from social media accounts like the ones below(click a tweeted link to see an ad for the JobBoard):

https://twitter.com/AngularJS_news

https://www.linkedin.com/groups?groupDashboard=&gid=4896676

https://twitter.com/angularjobs

edit: added Twitter account examples.

I'd love to talk to you more about this if you have the time. You can connect to me on twitter https://twitter.com/patrickjbradley I have a website for finding tutorials about the Swift language. I've been considering adding a job board as a revenue source. Would love to hear your thoughts and advice. Even what you posted here is a big help already.
Awesome!

The JobBoard is a great way to get some passive income, but, there is a lot more money to be made if you want to devote your time to recruiting.

Having a non-recruiting domain in the space you want to recruit in is a huge advantage when getting both JobBoard and recruiting leads.

Definitely focus your recruiting efforts in one locale at first. DC, SF and NYC are the top markets if you are based in the US.

The JobBoard should be worldwide (easier to facilitate than restricting it anyway).

Feel free to send me sensitive questions via email: brian at linkplugapp.com

If you don't mind me asking, do you populate the initial listings on the job board by your self (by finding job listings and posting them), or leave it empty upon launch and just offer a period of free listing to get started?
I was populating the board with jobs for companies I scored recruiting contracts with.

These contracts made building the JobPosts and driving traffic worth my time(contract = collect a sizable a fee when someone you refer to a position gets hired).

JobPosts drive the organic traffic to JobBoards, so make sure you take SEO into consideration when posting.

I also started with a much lower rate to post on the JobBoard, never free, but as low as $29 at one point. As the traffic grew, so did the price. Now a JobPost costs $349.

Where did you find these recruiting contracts? Are they easy to obtain?
Call/email people in charge of hiring in your niche.

Most companies are very familiar with this type of contract.

I wrote an Android app based on a blog post of mine which got popular:

https://play.google.com/store/apps/details?id=com.jasmcole.w...

http://jasmcole.com/2014/08/25/helmhurts/

It reached the reddit front page for a day, and earned £3,000 during that day. Since then, it's averaged ~£150 per month, with only small input from me (minor updates)

I saw your write-up on this before; very cool work. Could you talk a little about the programming side of things and what you had to do to go from your initial mock-up (what did you use for that?) to the Android app, and how that process went? I saw that you'd written it was your first time with Android/Java.
Thanks! And sure, I wrote the initial simulation code in Matlab, which is very simple, just adding 2D arrays which Matlab is fairly quick at.

I then saw the traction the blog post was getting, so wanted to capitalise on that quickly. I had an Android phone, so for simplicity (and ease of monetisation) decided to write an app for that. From zero knowledge of Java it took probably 30 hours over a weekend to get the app out, then perhaps another 10 hours over the next week on a few updates and bug fixes.

Getting the app up and running was relatively simple, most of the time was spent looking up API functions in Google's SDK documentation (and SO!). The only complication was making sure the CPU-intensive parts ran in a separate thread to avoid locking up the UI, and dealing with different device display sizes and resolutions. Everything else (dealing with input, generating images etc.) wasn't particularly difficult, but did take time to implement.

I could have used this last month. I went through 4 crap routers before caving and buying a 250$ router to cover my home.
I wrote a bunch of ebooks and created a bunch of videos. I sold them from my blog and via Twitter; in fact, although I started in 2010 and have made at least 10 products, to this day, I only have web sites for one ebook and one video series. (Count each video in that series as a separate product and I've probably made at least 20 products.)

TBH, the worst part about this is that it's so easy, I got pretty lazy about it. This is why I haven't answered the "what did you make?" question - I got so lazy about it in 2014 that the side projects brought in about half what they made in 2015. Kinda painful in retrospect.

Likewise, if I had web sites for this stuff, if I built email marketing systems, I'm sure they'd make more money. I even have a Kindle version of one of my books, and I still haven't gotten around to sharing it with my customers. Kind of embarassing, actually.

But even then, I'm well over the $1K/month mark. No worries there. All you really need to do is create stuff that people find worthwhile.

Thanks for sharing this candidly. It motivates me (an incredibly lazy person) to put something together at least.
I developed a service that does SSL installation for you on Heroku: https://www.expeditedssl.com
haha. this is great. simple product.
Sounds like a great product! Some questions.

1. Your video mentions you 'buy the SSL certificate' for users. How does that work? Are you a CA or do you resell another CA?

2. Your video mentions latest security practices - are you selling EV certificates? Or just 'encryption to someone who owns this domain' certificates?

3. If you resell another CA, how can the identity verification process be 20 minutes?

Pardon all the questions, but I'm currently waiting on godaddy, who take 15 days, so I'm interested in this stuff.

Ah I just watched your video and I see you resell rapidssl. But the video also showed the certificate being generated on your server, rather than making a CSR on the desktop. Wouldn't you then know the private key?

Again, sorry for all the questions and thanks for answering!

Cool service, been looking for something like this!! Mind sharing more details, i.e. time to launch, rev numbers, cost, etc?

Has heroku providing free shared SSL impacted your numbers at all?

10MinuteMail - http://10minutemail.com

Temporary email. Got lucky with traffic, and run two Google Adsense ads.

Thanks for making that! Out of interest, are you willing to share a rough idea of how many emails have been created or how many are made a day?
40k-50k addresses are created, with about 80-85% of them receiving an email. I also get about 300k-500k email a day to expired addresses
Big fan of 10minutemail - great job! How are you able to keep track of the emails going to expired addresses? Aren't those addresses destroyed? Do you ever repurpose expired addresses?
> I also get about 300k-500k email a day to expired addresses

Ever had any ideas for monetizing the junk mail you receive? I'd imagine most of the mail filters do something similar to learn on, but it seems like there has to be some value from that volume.

> I also get about 300k-500k email a day to expired addresses

Ever had any ideas for monetizing the junk mail you receive? I'd imagine most of the mail filters do something similar to learn on, but it seems like there has to be some value from that volume.

> I also get about 300k-500k email a day to expired addresses

Ever had any ideas for monetizing the junk mail you receive? I'd imagine most of the mail filters do something similar to learn on, but it seems like there has to be some value from that volume.

How much traffic do you get to make $1k+ a month with Adsense ads?
I get 3.7-4 million page views per month from 850k-1 million unique users.
OK, that is a lot!

What sort of hardware do you need for that kind of load?

That's approximately 2 hits per second. If you're serving static content (or heavily cached) you could handle that with a Raspberry PI. Heck you could probably do it with an arduino.

Edit: this depends heavily on your traffic pattern, of course. Super bursty traffic from Reddit, TechCrunch, etc is going to swamp your IO, but CPU will never dominate the equation.

Might as well serve it from Amazon S3 with Cloudflare in front of it.
Of all the things that would be suited to Amazon S3 with Cloudflare, a simple mail client/server that saves email securely for 10 minutes is not one.

At all.

Depends on your users I think. If 50% of that traffic is during a 10 hour window of time each day, that could be around 70 views per second. And pulling email for an account could be more costly than a static page view. Then if he's getting that many views, he could be processing tens or hundreds of emails a day per account more or less.... Could get expensive.
> If 50% of that traffic is during a 10 hour window of time each day, that could be around 70 views per second.

How do you get that? Assuming 4M/month, that works out to 130K/day. Even if all that traffic comes in a 10-hour window, that works out to 130,000/36000 =~ 4/sec, not 70/sec.

As zrail mentioned below, it's not that much traffic from a load perspective. It's a Java app, so it uses some RAM, but honestly the hardest load to tune for was the inbound spam.

I have a massively overspecced server that I use for this, and many other sites/projects - 24 GB RAM, dual X5670 CPUs, etc... Typically runs at a load average of only 0.5-0.6. Like I said, overspecced:)

You probably need a better mail server that can more easily handle that load. Check Haraka out (shameless plug, but it's designed for high loads and this kind of app).
I'm writing some plugins for Haraka _right now_. Definitely recommended!
FYI: searching for Haraka on duckduckgo links to the page with a description text of "This is the meta description of your form. You can use it for SEO purposes.". Whoever runs the website should probably clean up the meta-tags.
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I'm a big fan of 10MinuteMail, it's saved from a lot of spam. Thanks!
How did you get approved for AdSense? I'm trying to get approval for a small app with little textual content, but it seems Google want reams of text so it gets rejected.
I didn't have to do anything special (that I remember - this was many years ago).
Nice idea. Thanks for sharing!
big fan also - how are you dynamically creating those address on the backend ?
I use this almost daily ( for testing my web app ), thanks for creating this site !
Awesome. I used to run a similar service, but almost got banned from AdSense by users who received emails with adult content. What do you do to account for content in emails that users receive that may be objectionable to your advertisers?
I use your service religiously. Hi!

PS: I will disable uBlock on your domain. I like people who advertise properly.

May seem like a basic question, but I'm curious what different use cases your users us your service for. The obvious to me would be to sign up for a service that requires an email and use the fake one. What else is it used for?

Thanks.

Curious, how did you market it?
how did you create the website and everything?
I wrote a book and video series on Sublime Text - https://SublimeTextBook.com

It's done about 80k in sales in 3 months - I'm in the process of writing a blog post about how I did it, what worked and what didn't. It's not inexpensive, but it pays for itself quickly so people are fine with spending the $45 on the book + videos.

Feel free to ask questions here so I have content for the post.

That's pretty cool. How did you market it? What's your net looking like(assuming 80k is gross sales)?
There have been 5-6 things that have contributed to - the biggest one is that I'm somewhat of an expert in the community - I have lots of free blog posts and videos so I've gained trust there.
How did you get into writing?

I tried to write blogs and had to write papers for university, but I always struggle.

I have the feeling that some people can produce much text from nothing, where I put my ideas into a few sentences...

It was really hard to write - took me 1.5 years, tons of research and re-writing. This isn't something I slapped together over a weekend. Far from passive income.

Creating content for me is always hard, but once it's done, I love to deliver it (via talks, teaching, videos or books...)

Great job man. Skimmed your book a couple months ago.
Well, the passiveness of that income probably depends on how timeless your book is.
Thanks for sharing. Writing for a 1.5 years is a long time. How did you stay motivated to keep going?
Where there any legal implications you had to consider? I mean did you reach out to the creators of SublimeText before creating your product?
Yep - I have permission to use "Sublime Text" in the book title
You used to (still do?) spam this heavily on the programming subreddit. It annoys me to see that it's selling rather well, yet you apparently can't be bothered to buy an ad.

Please see: https://www.reddit.com/wiki/faq#wiki_what_constitutes_spam.3...

I just looked at my submission history and I've only submitted it to /r/programming once - so that isn't spam.

And yes - I've bought all the reddit ads I can get my hands on - they are in pretty limited quantity.

Nearly every submission you've ever made to reddit is either directly to your book, or to a post on your blog, most of which include a massive ad at the bottom for your book. That's spam. Even if there was no ad on your blog and you receive no compensation in any way, it's still spam.

Here's another good informational link that delves into this aspect: https://www.reddit.com/wiki/selfpromotion

I'm glad you've bought ads (though I don't remember ever seeing one), but that doesn't exempt you from the rules about self promotion.

Get over yourself. This is part of why I hate the Reddit community-- it's a bunch of snarky, pretensious neckbeards.
Folks gotta eat and have kids to pay for as well.

People demanding something for nothing doesn't scale, so it we must settle for something in between: Mutual value.

Hi Wes, I would very much be interested in the case study of what you did for marketing of the book. What did you do? How did you go about it after you wrote the book?

Thanks! Matt

I sell 6 and 12 month leadership development programs to companies. I make 50% of the sale. At $50/mo per employee on the program, I make an extra $1000/mo at 40 employees. http://LIFELeadershipCorporate.com
Judging from what I've been exposed to from HR departments, this is a seriously underdeveloped area...

(I mean the content, not the selling of it.)

My specific content or the content that is normally available by other companies?
Sorry, I meant whatever I've been exposed to. Likely not that same as your content.
Oh ok. What were some of the best ones that you encountered? What do you think were some of the biggest shortcomings in the ones that you saw?
Is this your self-made content, or are you essentially an affiliate for someone else's course? Mind sharing a bit more how this works? Very interesting!
Affiliate, but I know all of the creators personally. We have a smattering of other leadership/personal development products as well.
Nice! Is this full time and you're making more than stated above - or are you part time and you are making ~1K / month as a side biz? Just curious about order of magnitude?
I am a mechanical engineer full time. I make ~3k/mo on the side with both the products listed on my site above and other leadership products.

I'd be happy to chat further. Hit me up on my website or on Twitter: @clintfix

Hi Clint,

This is an awesome project and it looks like the content you are providing is high quality and impactful! I would love to hear more about how you started gaining the initial content and how/why you structured the Courses (1&2) in the ways that you did.

Thanks,

Do you intend for the text to blink on your site? Because it blinks for me. Latest Safari.

I recorded what it looked like. You can see it here:

https://www.dropbox.com/s/i9jpjzm7035bhg2/blinking.mov?dl=0

Interesting. It is not supposed to do that. I will look into it. Thank you for bringing it to my attention!
Whilst you're on it can you fix the LLR logo roundel not to have floating pixel cruft in the transparent areas (and poor cropping) and maybe provide a properly scaled WP logo - that anti-aliasing gives me the jitters ... just saying ...
Thanks! I have that stuff on my list already. I appreciate the feedback!
Small niches are cool, but you probably can't live from ads. Choose a lame subject with lots of users and make a clean and easy to use website.

I have a small directory website. It's pretty boring stuff, but it is a good source of almost passive income. Never published it. I just created the website and sent the sitemap to Google Webmasters. It's 8 months old and I have 400k pageviews/month.

I have lots of projects in idea stage, I want to execute at least two in 2015. My plan is to reinvest all money from this first side project to create others.

With 400k page views what does your Adsense look like?
I don't send all my traffic through AdSense, some go to other services, which give me less profits with less rules. I have a CPM around $2. depending on the ads platform. AdSense is definitely the best one for me.

I started with AdSense 3 months ago and I'm still afraid of being banned and lose all my revenue. I don't explicitly violate any terms, but it is not original content and can easily be framed as doorway pages.

What is the url?
Sorry, never published the URL of this service and really don't want to do it now. To be honest, this is the first time I wrote about it.

One of my goals to 2015 is a better project to publish here.

I created a card game that I sell on Amazon. I have it manufactured in China and sell it though Fulfillment by Amazon.

Quite a change from my day job working in software but I enjoy the diversity.

http://www.amazon.com/gp/product/B00PJKCXJC

Mind talking some about how you do it?
+1

I've been trying to understand the full remote supply chain, going directly from the offshore supply chain directly to FBA.

Its difficult to completely automate the supply chain as incoming FBA shipments expire 30 days after they are created. If you're shipping heavy freight from China this is cost prohibitive. I currently "touch" my inventory one time in-between the source and FBA. I'm working on streamlining that part though.
Be sure that your mfgr isn't running off extra for AliBaba, free markets or other channels. Contract mfgrs are notorious about ripping off IP and product.
How is it possible to be sure of that, though? If they're a contract mfg then by definition they've already signed a contract that says they can't do that, so if they do it, they've broken the contract.
Check these guys at www.forestshipping.com - they can ship direct to FBA from your factory and do labeling services if needed.
I'm happy to answer some questions... can you be a bit more specific?
Well, what kind of companies do you work with—a printer, and a distributor? Any others? How did you find the ones you work with—and how did you know that they were the right ones? What have you done for marketing—gone to trade shows, paid for advertising, giving samples to the right people, or what? How well is it doing? Have you sales been steady, increasing, or was there a big burst at the start, and a trickle since? Um... that's what I can think of off the top of my head.
I work only with a printer... Amazon is my distributor. I found them on Alibaba.

I'm starting to ramp up my marketing but to date I've done some adwords and advertising on Amazon.

Sales are steady, I don't reach $1000 every month but the holiday season more than makes up for it when you average it out.

Thanks for the info :-)
Roughly how much did you have to invest in the first couple of sets? Most manufacturers have a minimum order, and I imagine that would be the case for you considering you were getting something custom made.

Thanks!

I don't know exactly but it was no more than 3k and a decent amount of my time.
Good job! Which card manufacturer are you using?
Would you mind sharing the name of the manufacturer in China? Cheers!
I made a a community built around sharing creative writing, story telling, digital art and artistic expression. It also has a few browser games and a "digital collectibles" aspect to it. I started it about a year and a half ago with a digital-artist friend.

It's got a standard F2P model for the collectibles aspect: you can get everything for free by playing the games / posting in the forums, or you can pay for it. It probably doesn't make as much as it could as I refuse to employ "dirty F2P Tricks", but that's a personal choice.

Check it out if you care to :)

https://www.mycenacave.com/

I'm bringing home about $2,500 a month on my side project. This year I plan on doubling it. The issue is that this is really starting to becoming another full-time job.
That was a little vague. Care to share more details?
You're right. I'm Sorry.

I run a membership site called travelblogsuccess.com. My full-time job is at WooThemes for WooCommerce. I'm a firm believer of "eating your own dog food" thus we use WooCoommerce and several other plugins on my own side project. This has given me a better understanding of the products we sell at WooThemes as an actual customer on a live site. I learned more about our own products using it for my side project than learning and testing our plugins on a local development server.

As for the site itself it does require maintenance so not quite passive. It's important that we communicate with our community and update our lessons and courses often. We just introduced a public Slack community yesterday for example. We're now a team of four and could easily need more help. 2014 saw huge growth.

Initially I was concerned that my side project was going to take up too much of my time resulting in having two full-time positions. It did take some lifestyle changes in the beginning to free more time like spending less time messing around Facebook or Twitter and optimizing my time spent on my side project. In the end everything has worked very well. I spend on average an hour or two each day on my side project. Sometimes more if I'm simply watching TV while working on a few tasks during my downtime.

Sorry for the initial vague comment. Please do feel free to ask me any questions.

I wrote a book called Build a Ruby Gem ( http://brandonhilkert.com/books/build-a-ruby-gem/). After release, it's required very little work and has totaled about $20k in 9 months since launch.
How did you market this book? Do you think having 1k twitter followers helped with sales?
Mostly in places I knew Rubyists hang out online. Message boards, link aggregators, etc. Twitter helped very little towards sales. Although I use Twitter here and there, focusing on capturing emails was more valuable.
https://hopsie.com

I wrote a site creator for non-profits that allows them to create customized fundraising sites.

That doesn't look like a side project but great work nonetheless!
Do you use any open source cms?
I have two apps in the iOS app store. One launched in 2009 (Filer) and the other in 2010 (FLAC Player). I've been really lucky that both have done so well, especially 5 years on. I maintain them for major iOS releases and hardware changes, but the little time I have I try to work on new stuff and supporting them. My wife helps with support emails now, which has been a huge help.

Neither app has any server-side components, so they don't cost me anything but squarespace fees for my website and my iOS dev program membership.

Edit: Oh yeah, they're both paid apps and I don't fiddle with the pricing

I wrote an ebook ("Practice Makes Python", http://lerner.co.il/practice-makes-python ) for people who have learned Python basics, but want to gain fluency. I'm working on videos for a higher-tier offering, and then will start to market it more seriously.

I only launched the book about 1.5 months ago, and I'm at about $1500 in revenue. I'm definitely hoping to see greater income with the higher tiers (including video) and greater marketing. I'm also speaking with some companies about them buying site licenses of the book, which would increase the revenue even more.

How have you marketed this so far?
To my mailing list, via a bunch of blog posts (on my blog), at free Webinars I've given, during a talk a gave at the hack.summit(), and on Twitter.

I tried some ads (Facebook, Google, and Reddit) for a short time, but they didn't work -- mostly, I'd guess, because the landing page is still immature, and because I didn't give away any free chapters or other elements.

The landing page is now better than it was, and people now have a choice between buying the book right away and getting a chapter's worth of exercises and solutions over a 10-day period via a drip campaign. These improvements have definitely raised the conversion levels.

Are you still writing for Linux Journal etc? I remember your articles from back in 98, 99, 00.
Yup! Every month since early 1996...
FWIW I just finished a beginners python course on Coursera - Programming for Everyone (PR4E, https://class.coursera.org/pythonlearn-003/). There's no natural follow on as the course uses a book for which only the first part has been translated in to a course. There were a lot of people on the course asking what to do as follow-up; might be a lead for you.

I just signed up for your samples as 'pbhj' if you want to get in touch.

Incidentally, when one adds themselves to your email list for samples it takes you to https://lerner.leadpages.net/new-practice-makes-python/thank... but there's no route back other than using the back button. IME this tends to mean people will just close the tab, providing a route back or on to a related page might help conversions or give you chance to get affiliate conversions or what-have-you.