I'm simply reposting from 37 signals here. I loved the title of their post and reused it. Other than that this is just a reminder for myself really. From 37 signals.

Allocate your fear properly

When it comes to building a web app, some things create more fear than they should.

Fear: It won't scale Truth: You're not going to be Google overnight.

Fear: Too many bugs Truth: As long as they don't wipe the database, you can live with most bugs for a while.

Fear: Too few features Truth: You can always add features later.

Fear: Never go down Truth: Once-in-a-while downtime won't scare people away.

Fear: It's too simple Truth: Simple solutions are fine if they get the job done.

Fear: They'll copy us Truth: It's about the execution, not the idea.

Fear: We must sound serious Truth: Trying to sound serious all the time makes you bland and unremarkable. It's ok to be playful and have personality. So get a grip.

Yes, these things matter. But some people get hysterical over these issues before they even deserve to be on the radar. If you fear one of the above issues, make sure it's due to a genuine risk and not just something that's giving you a mental stiffy.

Otherwise you may be wasting time chasing phantom problems.

The flip-side is that you need to recognize genuine threats even if they're boring issues.

Things like these are a lot more likely to actually cripple your chances of success:

Taking forever to launch.

Running out of money.

Not solving a real problem.

Designing a confusing UI.

Obsessing over the wrong things.

Trying to do too much at once.

Never ignore real here-and-now threats in order to focus on maybe-in-the-future threats.