Cutcaster [3] have taken another step towards being credible with the launch of their affiliate program.
They provide 10% of buyers transactions and 5% of referred photographers earnings for a whole 2 years, a pretty good deal in our opinion.
It's still early days for cutcaster, but if they keep up development at the rate they are going (launch was back at the start of April this year) then they might soon start to grab a slice of the market. The do need to do some more improvements with that upload system though!