First some facts:
All businesses who accept credit cards pay fees to the credit card company, and they've all signed agreements that include a clause saying they won't charge their customers extra for credit card transactions. The idea is they're supposed to get more business if they accept credit cards, and the increased volume is supposed to be well worth the fees they pay.
That works for some businesses, doesn't for others. If a pricey hotel starts accepting credit cards their volume usually goes up and the resultant profits more than pay for the fees, risk, and hassle involved. If a newstand starts accepting credit cards, though, they usually don't sell enough extra newspapers and magazines and cigarettes to pay for the credit card fees, frauds, and labor of processing. Therefore most hotels accept credit cards and most newstands don't.
Many people suspect businesses pay for the expenses involved, not with increased volume, but by raising their prices. Examined closely that suspicion doesn't make much sense. If your local newstand started accepting credit cards and raised their prices a penny per newspaper, they might gain some credit card customers but a lot of their cash customers would start going to the newstand across town, and in a week the newstand would see they're making less money and forget about that idea. A hotel's customers would take more than a week to figure out they can get a better deal at the hotel across town, but they'd figure it out eventually. (If you own a hotel and think they wouldn't ... um ... why don't you just plain raise your prices?)
I think the net dealers regard Paypal as just like a credit card and decide whether or not to take it by comparing fees, risk, and hassle with the various credit card companies. I expect they have a pretty good idea whether it's worth it for them or not.
For a knife knut who only sells an occasional knife on the net, though, it's not so clear. It isn't practical for him to deal directly with the credit card companies. If he accepts Paypal he probably has better odds of selling his knife for the price he wants in the time he wants to sell it in -- but how much better are the odds? Enough to make up for the 3% fee? How's he supposed to know?
Maybe he dithers about it ... should he accept Paypal? Shouldn't he? Hey, maybe I'll compromise -- I'll accept it but only if the buyer is willing to pay the 3% fee for me ... then I can't lose, right???
Or can I?
Everybody knows that's a violation of the seller's contract with Paypal. Some prospective buyers might look at that and think, hey, this guy is breaking his contract with Paypal, he's unethical, he's likely to break his contract with me too. I ain't dealin' with him!
No doubt most people don't think that way. Either they don't think about it at all or they figure violating the boilerplate in a contract with a faceless giant corporation like Paypal is different from ripping off a buyer.
But some of them might figure he'd keep his contract with me but just the same even a contract with a corporation is a contract and he's being unethical and that's just wrong and I'm not going to support that; I ain't gonna deal with anybody who would do that.
Other possibilities occur to me.... What if somebody reports me to Paypal, and Paypal cancels my account and refuses to do business with me any more? What are the odds of that happening? I dunno....
I hear that clause of the contract is legally enforceable in some jurisdictions ... is it in mine? Or in the buyer's? What are the odds of getting into trouble? I dunno....
What if instead of charging 3% extra for Paypal I raise my asking price 3% and offer a 3% discount for payment by money order? Would that be exactly the same except not a violation of the contract? I dunno. I can't afford to pay an attorney to tell me ... and I sure can't afford to go to court to find out....
Well, I started out with some facts, got into a lot of reasoning and speculation ... and where am I now? I dunno....
