Gaming check out http://www.scvngr.com/
This is the guy who did the TED prezo on gaming layer (http://www.ted.com/talks/seth_priebatsch_the_game_layer_on_top_of_the_world.html) - scvngr is his idea along with levelUP - great concept to think about when looking at developing an app
Appointment dynamic - for one to succeed, they must return at a specific time to be rewarded - an example of the appointment dynamic would be "happy hour"
Progression dynamic - incremental advancement and privileges as predefined tasks get completed. Example - buy a gift card and unlock the next level of rewards or get a badge or something of prestige
Drives loyalty, promotes competition to persuade behavior -
I think putting these concepts into an online product/mobile app should be a fundamental element of its architecture...