Is it possible to make money off of advertisements if your primary audience are techies?

Possible? Sure. I've put up web pages directed toward programmers, and have gotten ad clicks.

But you'll probably find a greater click-through rate writing on other topics.

Honestly, I find the subject matter of the ad more relevant than the presence of an ad. Partner up with good sites like New Egg or Tiger Direct for ads and you're bound to get some good numbers. Stick with Google AdSense (and that's not to say anything negative about AdSense) and you wont see near the same numbers mostly because

1. Everyone recognizes AdSense and it doesn't really stand apart from content (this reflects on how effectively and tactfully place your ad)

2. More common is it becoming to see Ads on AdSense that point to TLD's that display no relevant information, or useful data, so people automously ignore them.

Advertisements are all about the audience, much less the product. Get the right ads, and you'll see results even with the techie crowd who are more familiar with blatantly bad advertisements.

Very much so: job ads.

If you get to a decent size you can get sponsorship from companies and sell your own ads. They'll just be images/text on your site with a link to their site, so you can avoid hitting adblock default list. If the the ads are for good products people might even appreciate them.

You are right in regards to adsense. Adsense can work as a business model, but only at a MUCH larger scale than most realize. When you factor in natural ad-aversion, it raises the the bar for success to a number you will be unlikely to achieve without a mainstream site.

That said, job ads are a very cool approach. They pay more and in-the-know managers are willing to pay a premium for elite developers.