When 500px unveiled its Prime photo licensing store, it stirred up a hornet's nest -- many photographers were outraged that the image host would keep most of the cash from their work. Give credit to the company for a change of heart, though. It just launched Prime in beta, and the royalty rates are much more favorable. While 500px now sells all photos at a $250 flat rate (instead of a $250 minimum), photo owners get 70 percent of that revenue; unless you regularly sell pictures at higher prices, you stand to earn considerably more per shot. You'll have to get an invitation to the beta to give Prime a chance, but the revamped service could be a sweeter deal if you'd make a pittance from rival photo services.