First and foremost you need to familiarize yourself with Dave McClure's Startup metrics: http://500hats.typepad.com/500blogs/2007/09/startup-metrics....

If you then look at your analytics, you will then find that you likely have either an Activation problem or a Retention problem or both. That then tells you the areas of focus in terms of the problem to correct.

Also read: http://www.socialmediamodels.net/social-media-overview-model... http://www.slideshare.net/startuplessonslearned/eric-ries-en... http://www.startuplessonslearned.com/2008/12/engagement-loop... http://andreehuk.com/post/67267407194/gradual-engagement-a-g... http://sixteenventures.com/saas-customer-success-quick-wins