The biggest 20 games operators on Facebook are combating a steady drop in daily user retention, an analyst group has said.
IHS Screen Digest claims that, during the first three quarters of 2011, the likes of Zynga and PopCap noticed a downward trend in user engagement.
User engagement is a specific metric that measures the ratio of daily active users versus monthly active users.
If the ratio is in decline, as the new data suggests, it means that those who log on to Facebook games every month are doing so less on a day-to-day basis.

http://www.mcvuk.com/news/read/faceb...decline/086155