Like other exchange-traded products, the costs are higher and access is via a traditional broker.

But "for the mass market, the traditional broker will become irrelevant," he predicted.

So the image of a traditional broker in the industry has evolved to something like a Cadillac, or the last car you drive before you die.

It was one of the first firms to allow investors to directly buy stocks through their computers, thereby by-passing the traditional broker.

Still, Redfin agents - like their customers - say they meet real resistance from traditional brokers.

Part of the reason for the slow movement is opposition by many traditional brokers, who fear that the new method will drive down commissions.

"With traditional brokers, this would be a very, very dangerous game because you fundamentally are cannibalizing your main business."

Those using traditional brokers paid 96 percent.

He is aware of the criticism that many traditional brokers put their own interests before those of clients.

Ms. Corcoran said the services "haven't succeeded in the long run," and had not cut into the traditional broker's market.