We do have a Premium membership to show the ad of an e-commerce site, showed on every page of our site. The problem is we only get 10€ per month. We should earn

We do have a Premium membership to show the ad of an e-commerce site, showed on every page of our site. The problem is we only get 10€ per month. We should earn some money when a sale occures through their site, but it never occured...