Key to success in growing engagement is pinpointing a metric early in users’ lifecycle, before correlating it to the goal of long-term engagement. Then creating predictions of the progress of that engagement goal based on current data; before modifying users’ experience to improve engagement going forward, with monitoring in place to plot progress. An example from Facebook, which started out as a student-only social network, is that users would become engaged if they reached seven friends within ten days of creating an account.