This is a great project Matt. We're working on similar things at UserDeck [1] and I think mobile support is going to be huge. I think you're getting a lot of feedback that may be a demotivating as HN has a lot of developers, but not many business minded people which is what I've found is who you sell and the developers implement it based on the needs of the business.

For example on the build vs hosted service there are many things a developer would not want to build such as WYSIWYG, analytics (figure out what is working, what isn't), ratings (up/down), easy changes (no app store deployment), translation across devices (iOS/android), ticketing (contact form for help). When I had initially thought of similar ideas, Zendesk hadn't moved an inch, but here lately they started getting into mobile support [2] so if anything I find it validation to the market that will just continue to grow. There simply is no reason every developer should build all of that out reinventing the wheel when there can be a service to provide that functionality and focus development resources in other areas.

If you want to chat more, my email is in my profile.

[1]: http://userdeck.com

[2]: https://developer.zendesk.com/embeddables