Just a quick note. That you have pricing up front is such a big thing. Places like Imgur and photobucket before it were out to be exploited merely for their free bandwidth.

There is a clear means of funding this and that instills confidence.

One other note, I also am a lot more likely to jump onto a service if there is an easy escape plan. While you don't want to loose customers, having an easy out allows people to exit on amicable terms.