Originally Posted by rdawson808
Then I need an explanation. If they aren't related, I'd just say EBay can choose to do business with one firm and that's their..well, business.
But if they are related, then I'd look at EBay's position as the far-out leader in internet auctions (what competes with EBay?) and ask if their requiring the use of PayPal isn't just a tying arrangement in order to take over the internet-payment business also.
Tying generally means you're requiring the use of the second product. Here, they're prohibiting references to competing products (competing against the "second" service, paypal). You're not required to use paypal. You can send checks or use a variety of other payment methods. You can probably also use Western Union, etc., but just can't explicitly list them on your ebay listing.
Also, while I'm assuming for argument's sake that ebay has market power given its large market share, the facts that ebay is not providing a unique product or service, and that presumably it would be relatively easy for a new market entrant to compete, may well run counter to that.
(Just my off-the-cuff thoughts, obviously. FWIW in deciding how much salt to take with my views, I'm not an antitrust expert although I've dabbled in it from time to time.)