You have to start by understanding their business model and where these "fees" come from exactly does matter and here's why. The objective is to offer buyers the paypal service as a convenient way make purchases for thier online transactions. The primary emphasis here is to encourage buyers to spend money using paypal. So, if sellers are passing along their user fees to the buyer, then this discourages buyers from making online purchases using the paypal service when spending their money. Basically, it goes like this... If there's an incentive for buyers to make the online purchase using paypal then they will.... If there's any kind of penalty involved for buyers when making their online purchases using paypal then they wont. ...Get it? The introduction of a penalty or "discouragement," in the form of an "extra fee" when buyers are making online purchases through paypal is viewed as something that would negatively affect overall profits and obviously paypal doesn't want that scenario to occur. That's the reasoning for their policy and I hope that answers your question.