Zynga isn't an outlier. Virtual Goods certainly isn't a new business model, and they're definitely not the only ones doing it on Facebook. Besides, from all t

Zynga isn't an outlier. Virtual Goods certainly isn't a new business model, and they're definitely not the only ones doing it on Facebook. Besides, from all the anecdotal data I have, successful apps using virtual goods typically get 1/3 revenue from direct sales, 1/3 from CPA offers, and 1/3 from ad clicks.