The simplicity of this service and the free listing model could make it a real contender as a Flippa.com alternative. As others have already commented, there is still a lot of room for improvement (payment methods, improved bidding system, etc), but I could definitely see this in future iterations of the service if it were to gain enough traction.

As an immediate suggestion to the developer, it'd be nice if the registration, login, and dashboard areas were secured (HTTPS). Everything appears to be transmitted over HTTP at the moment.

In any case, kudos on the launch - this could definitely shape up to be a pretty solid service.