As much as I loath paypal's policies and behavior, I gained more money because of them than I lost. Try telling people you only take money orders, epassporte, etc instead of paypal, and see how much you start actually losing especially amongst US payers.
I noticed personal accounts are no longer exempt from fees (unless the sender specifically says it was a gift or something in the sending form), but then again you couldn't bring in as much anyways on a personal account anyways.
Simply put, its one of the few free-to-start merchant gateways that payers feel comfortable with (even if their purchases are not eligible for buyer protection [ie: services and intangibles])
And I don't have to pay extra just to use an IPN url (instant payment notification, where it can send transaction details to a url on my server where it can be automatically processed).