[iamwil]

I'm sure there's just as many failed startups that bone-headedly try to keep going.

I think the important thing is to keep evaluating based on user reactions and market size. You might find that there's a segment of users that want to do something slightly different. Even if you're the first mover, there will always be competition.

That said, I think Amazon knew that eCommerce was going to be a pretty big market, and the Google knew lots of people searched. Even if they didn't get most of the pie, some of the pie was still big enough. If he made an iPhone app to find recipes for star wars fans with allergies (or something with a niche market) without potential for enlarging of the market, it may be time to consider something else.