Uh... I don't see the distributed marketplace. (As most here, I'm still trying to wrap my head around it.)
You would still need to
1. Obtain some kind of IOU (DGC)
2. Trade it at a particular place. (OT server)
From my understanding of FellowTraveler's initial post, BM is used for matching Bids and Asks by creating an exchange protocol on top of BM that interested parties can subscribe to.
The only problem is this doesn't sound very user friendly. How can it all be turned into a simple web app?