But there is a there there. Some apps are useful. People like them. The facebook app users get something they want, and a tiny minority click-through to ads (fo

But there is a there there. Some apps are useful. People like them. The facebook app users get something they want, and a tiny minority click-through to ads (for facebook apps or other services), and a smaller minority actually spend money. That makes it dissimilar to a Ponzi scheme: there is input into the system from people outside the pyramid.