I've supported (both financially and otherwise) several projects to build applications, to recruit users and build communities, etc. None of them have really panned out overall (in the sense of creating enough growth to move the needle for Steem overall). The failures of the projects I've personally supported aren't the point though. The point is that no one has done it.

If we look at the application/project that is bringing in the most users right now, it is Spliterlands, which doesn't even use inflation rewards. In fact that their stake is inflated to pay inflation rewards is an added dead weight cost to them and a discouragement to even be on the Steem blockchain, and that is our most successful application in terms of growth. That's nuts.