I've been thinking about writing some sort of white paper on this, because a lot of what we did was relatively unknown and may benefit the larger financial community. "I guess I'm convinced it's possible" is a great first step! I'll take it!
We had four revenue streams (interchange, instant send, credit card loads, and float on deposits) but IMO to really make this work it needs to have a subscription fee as well. That's a whole OTHER controversial topic in payments, but outside the scope of this discussion thread :)