It is bad to see that you have so few gamblers on your site. Even if several free images have been added to give users a small balance, not many clicks have been done on the "paid images". I think you should launch a small marketing campaign now, either buy a forum ad space or run a small signature campaign to attractive more gamblers. Another option would be to completely turn the site to be a faucet, add some adspaces and run your site like those PTC sites.
But if he is start a campign it should be a competitive one about their payout if they payout is low I dont think he have a chance to compete their pickxel in this gambling anymore. But the idea is already good but still it so low people coming to play