Release Early or Release Big?
xobni.com
xobni.com
If you have an app that can exist in isolation and plenty of money, you can achieve that product perfection (not really of course, but enough to make some money) by conducting formal user-tests, focus group junk, exclusive invitation-only beta-testing, etc.
If you don't have the money or if your application requires or is fundamentally a social network, releasing early and having the very early adopters is the only way (it seems) to get that product to the ripe stage where you can then "go big."
Another nice thing I see about launching with YC's blessing is you automatically get enough buzz to be visible to the early early adopters.