There were some mobile features that I wanted to implement on an orthogonal project that I'm toying with, and I noticed that there were no good APIs for IM-enabling your app, and I wasn't truly satisfied with the existing SMS solutions, so we built this. However, to your point, we need a killer app to really show the potential of the platform. Arguably though, it might make the most sense to simply target my original use case, and build the platform for developers who want to add mobile features to their products but don't want to spend huge amounts of time figuring out exactly how to do so in a scalable and highly-available way.
