Taken at face value, Dropbox's indicator is particularly interesting: > ChenLi Wang, who runs the growth team at Facebook [sic: Dropbox?], said that the leadin

Taken at face value, Dropbox's indicator is particularly interesting: > ChenLi Wang, who runs the growth team at Facebook [sic: Dropbox?], said that the leading indicator of an engaged Dropbox user is when they put at least one file in one Dropbox folder on one device. Basically - the leading indicator is any use at all. The other business' all had, relatively, a much higher threshold. This is probably because Dropbox is immediately useful and stupid-easy to use. Of course, it's hard to take this at face value since we don't know how everyone is defining an engaged user (and each definition isn't directly comparable to the other services' definitions).