I think once anonymity works in 2.0 there will be an explosion in usage.
First, we'll see "dark" markets begin to adopt OB, and as they do they will have money to spend. They will already be using OB, so why not shop there also?
This will bring demand for non-illicit products. Even drug dealers need toothpaste.
It's such an appealing product the explosion may even come from regular users who suddenly find they can open up an online shop in less than ten minutes.