I think I saw this an article about your site before. Why would we as REALTORS put our buyers info on a database to be scrounged by sellers. Although we sell property what we really do is provide and disseminate information. Our list of clients is our business. Isn't that what the MLS is for???
I would never let a buyer client enter info or enter it my self. Also this will lead to more FSBO thus less money for us. I don't see this working at all, well maybe some really stupid agents might use. But all this does is remove the agent one more step out of the picture.