I've heard the argument (also made by PG) that there will always be room for more successful web startups. Do you think it's true?

Sometimes I get the feeling that the internet has gotten too crowded. Every idea I think of, someone else has done.

But it's more than that. I also sometimes think that mainstream users have a finite number of needs that web applications can satisfy. I think of web applications are like kitchen appliances. Once you have the essentials -- a microwave, a fridge, an oven, a toaster, a coffee maker, and a blender -- new appliances you get have decreasing marginal utility. Sure, you can always get new ones for increasingly esoteric needs, but they are just not as useful as the important ones that almost everyone has.

I read about all the new startups on TechCrunch and YC news, and although I think many of them are cool, I don't use 99% of them. Why? Because although they may solve some problem I may or may not have, incorporating them into my life introduces mental overhead. It's like PG's essay about stuff. Having less stuff keeps your head clear. So does using fewer webapps. I'd rather use 5-10 really useful apps than 40-50 marginally useful ones. Although the total utility I can get from the marginally useful apps is greater than zero, this utility doesn't outweigh the disadvantage of having to think about them. They solve some problem, but they also add (virtual) clutter to my life. As a user (which is different from an entrepreneur in the same field) I'd rather not think about them.

Will there really be the next big search engine or the next big social networking site? (By big I mean bigger than the entrenched players.) I'm not convinced. Some industries mature and their barriers to entry become too high. (How many new car companies have been started in the last couple of decades? Not many.) Furthermore, after every adoption of a new product, users have a smaller reason to switch. I don't care if ask.com is sometimes better than Google or if some social networking site is slighly less creepy than Facebook. I still use Facebook and Google. They are wired too deep in my cortex. Trying out a competing product just isn't worth the work.

I'm sure there will always be technology startups. And there will always be new marginally successful webapps that cater to small niches (I just thought of one: a hot-or-not for pets app that runs on the iPhone! Maybe that's my ticket to riches!) But will there always be the next world-changing web startup?

What do you think?