In order to get people to do this, you'd have to advertise a traditional way anyway. If I'm going to do that, why wouldn't I just advertise my own product? I'd

In order to get people to do this, you'd have to advertise a traditional way anyway. If I'm going to do that, why wouldn't I just advertise my own product? I'd get a better increase in revenue that way than indirectly advertising for all of my competitors. (Unless you're the App-store, but you're not, and they're not going to do it)