We are quickly approaching the point at which our MVP is ready for beta testing by the outside world. How long should we run a private beta (if at all) before opening up to all?
Run it until you know there are no major snafus. I.e., system doesn't auto-purge your DB, assimilate all your users and nuke the planet.<p>Once things are stable, start scaling the beta up to a reasonable number of users. I.e., stress test, in increments. Once you meet a pre-set milestone, set it loose.<p>Goodluck!
You should run it for as long as is needed to test the effectiveness of your app. This period is one where code changes can be made to make your service better, decide pricing, test the market. e.t.c
Check this post from Joel Spolsky
<a href="http://www.joelonsoftware.com/articles/BetaTest.html" rel="nofollow">http://www.joelonsoftware.com/articles/BetaTest.html</a><p>It's more focused on desktop apps, but it has good insights
One strategy would be to initially continue to offer it as a "private beta", while allowing X invites to each existing user to expand the beta userbase.