Visibility on Bookfinder.com

Hi Gazza,for years now I have used Bookfinder.com to search for book titles. The site will pick up any book that is advertised on the internet. Amazon, Eblag, Abebooks as examples.
I notice there are no books on there from ebid? Is there a reason why books here don't show up on that site? Is it a case of you would have to pay them a charge for visibility?
It is my first go to site when I look for books I'm after. I'm sure book sales on here would increase if we had visibility on it. Sorry if this question has been asked before.