Engaging Facebook Applications

"These very first applications were basically simple implementations of some of the existing behavior/features that existed in facebook. A few that come to my mind are SuperPoke, SuperWall, FunWall, Send Hotness etc"

Actually those top apps then (many of which still are) just replicated functionality MySpace already had. The various FunWalls, TopFriends, some of the music apps, etc.

It's not a bad strategy really. Look at one, more popular social network, assume that heavily used features there would be in demand on another social network, and build it. If there's ever another platform from a second place competitor that lacks a lot of the functionality of its first place rival, it would be wise to do the same thing.