If you have amazon or ebay products on your hubs and people buy them you earn money. Once you have reached the minimum $ you can earn to get paid amazon and ebay will pay you. I believe you can set it up so that when they pay you they just send money to your paypal account instead of them sending you a check. (At least with amazon that is the case). Neither ebay nor amazon take money from your paypal account. They deposit money into it.