Agreed- if it's not that great an idea but it's super fun to build, you're more likely to stick it out until a better idea comes to you. And double agreed with

Agreed- if it's not that great an idea but it's super fun to build, you're more likely to stick it out until a better idea comes to you. And double agreed with your second Point- don't do something just because everyone else is. Just because everyone else is doing mobile local group buying checkins doesn't mean you shouldn't build that text to speech WordPress plugin you've been dreaming about (shameless castmyblog plug).