Pure speculation: this is carmax for housing. Moving is like trading in your car for a new one. They'll start with a focus on buying from the public to build inventory then begin facilitating the end-to-end of sell-to-buy.

Imagine this: I need to move from, say, Columbus OH to St Louis MO (their focus is not on hot markets). I browse their STL inventory online, pick the house I want, sell them my house, click, click, click then go have a beer and wait for the movers to show up.

Rabois has the money-moving chops from paypal and square... I don't see why this isn't possible, aside from the nightmare of paperwork...