I am taking the family on a US domestic trip in a few months and have already started the process of flight-searching. I'd be willing to try out something like this, even just for the novelty. However, with so many international flights, the list inadvertently seemed to alienate simple domestic flights.
I wanted to see more examples of my type of trip (business class, simple domestic flight), but wasn't really sure how to do that. I searched through the first 3-4 pages before deciding I would have liked some filter controls on the list. I wanted to see what kind of savings people were finding and what types of trips were being posted. Basically, a way to determine if my trip met the right criteria for a contest and if it was feasible to use the service.
That said, I understand my trip may not be the immediate target market. Nevertheless, I'm going to keep watching this because I really like the concept.