Let your community grow alongside you: Ship unfinished apps.
thestartupfoundry.com
thestartupfoundry.com
I think the title should read, Ship unfinished social apps.
You cannot generalize when it comes to all apps, especially those that have a narrow niche / target user. Sometimes you have to keep the door closed and everything on lock down just to launch with an edge over the competition.
That being said, my most successful app in the Android Market started off VERY crude, and with feedback, it turned into the great app it is today. However, had I launched TOO crudely, I don't know that those early users would even have stuck around long enough to leave constructive comments. It has to look like you are trying and willing to KEEP trying to make the app better.
At the end of the day users decide how they are going to use your product.
In a context where your customer is the general public, it's fairly obvious how to adapt that development model. Anything from a limited closed beta to a simple public release might be appropriate, but ideally you want to develop in a way such that you have a minimally functional but stable app fairly quickly, and add features and refactor (hopefully based on user feedback) from there.