I haven't tried this service nor am I likely to anytime soon. I have a real problem with bidding on a fare which, if accepted, locks me into a flight on an airline not of my own choosing and, worst of all, at a time that the airline finds convenient for itself rather than convenient for me. I have a hard time believing this approach is viable in the long term. One possibility which makes much more sense would be to reverse the process. Potential customers could post their travel needs (perhaps in a spin-off of this forum) such as "need flight from DC to San Fran on August 21 leaving at about 5 PM. Max. cost $350." Airlines serving the route could then respond with their best offer for the desired flight(s) and customers could choose accordingly (or not at all).