Uh-Oh for Facebook Developers

23,857 Facebook applications later, the elephant in the room is making itself heard.

According to an analysis by Jesse Farmer, creator of the Adonomics application-stat-tracker, “the excitement over the Facebook Platform and its promise have waned. Application companies are branching out to other social networks not because they necessarily show more promise than Facebook, but because the future of the Facebook Platform has become murky.”

In a lengthy blog post, Farmer lays out the reasons for his viewpoint. First, activity in the Facebook developer forums has fallen off. Second, application activity has dropped off.

While he concentrates most of his argument on the forum activity, where developers post questions and talk business, it’s the application activity that marketers need to pay attention to. In one chart, he shows that between October 2007 and May 2008, the percentage of applications with at least 100 daily active users vs.  the total number of Facebook applications has dropped from around 27% to around 18%.

That speaks to the signal-to-noise ratio of Facebook but also to the challenge of promoting and virally spreading an app. Facebook has clamped down on developers that take advantage of friend networks, which is good, but it’s clear from this analysis that the viral infrastructure is also starting to crumble.

Whether this is a Facebook-only phenomenon or if it will spread to MySpace and other social networks is worth watching very, very closely.