Site migration is rarely observed since users often abandon their accounts
rather than closing them. A more observable behavior is attention migration,
which is clearly observable on most social media sites. Moreover,
when a user commits site migration, it is often too late to perform preventive
measures. However, when attention migration is detected, it is
still possible to take actions to retain the user or expedite his or her attention
migration to guarantee site migration. Thus, we focus on individuals
whose attention has migrated.