Give me a break. OpenFlights.org, a completely free open-source flight mapping tool, had a really popular Facebook app that a) let people post a map of their flights to their Facebook profile, and b) post updates on Facebook automatically when they flew somewhere -- not exactly spammy, parasitic or viral, just sharing info with friends. But merely keeping the FB app up and running consumed more support time than the (far more complicated) website itself, because the APIs changed all the bleeping time, and eventually in 2010 Facebook decided that letting people post apps they liked to their profile was Not Allowed(tm). So we gave up, and seeing what has happened in the three years since, I don't regret making that call one bit.

http://openflights.org/blog/2010/11/05/farewell-to-facebook/