Many developers are giving up on Facebook's third-party applications platform, finding it too hard to follow the social network's strict rules for programs which piggyback on its lists of friends and news feeds to find new users. But one application has thrived: Joe Green's Causes has seen traffic triple in the past month, helped in part by interest in the election. But only in part.Causes, Inside Facebook notes, is part of Facebook's "Great Apps" program — handpicked applications which enjoy special treatment from Facebook, including more frequent appearances in users' news feeds. What makes Causes a Great App? One hopes it doesn't have anything to do with Green being Facebook CEO Mark Zuckerberg's Harvard roommate. (Chart by Inside Facebook)