Facebook has switched its apps metrics system from measuring daily usage to measuring monthly active users, a step toward standardizing web metrics, reports AdWeek.

The act better aligns Facebook with comScore and Nielsen, which report engagement for video, games and social networking content on a monthly (versus daily) basis.

Facebook believes the change will encourage app creators to focus more on long-term engagement and less on immediate sign-ups. The company availed its back-end code to third-party developers in May 2007. Since then, over 24,000 applications have flooded the site.