I think the scenario that you describe is probably OK or maybe borderline. You are talking about The Seller using his sales to generate more sales. Even though eBay does not get commissions or fees from those other sales the seller will probably still continue to sell on eBay and will pay future fees on those sales. Also the buyers that are generated from these residual sales are normal eBay buyers and they will probably continue to buy on eBay. The action that you describe actually may generate more revenue to in future auctions between the buyers and sellers in question. The transactions that take place between eBay buyers and eBay sellers outside eBay do still benefit eBay since they create and strengthen trading relationships between these customers. These relationships and familiarities between buyers and sellers may actually cause more bidders and Higher Prices. The higher the price, the more commission eBay gets in the end.

The problem I see is with the NON EBAY SELLER who trolls auctions on popular items and harvests sales among the loosers of the auctions. 's Market place has generated commerce for which the ebay seller has paid fees and commissions. Now someone comes in and gains from that business and does not pay for that benefit. Further, eBay does not have any control of this NON EBAY Seller. They have no record of who he is or of feedback etc. If he turns out to be a scammer preying on eBay customers, what ability does have to track the person down and protect their customers. Many buyers from these sellers may think that they are connected to eBay even though they may not be. Therefore, eBay has a responsibility to protect themselves and their buyers and sellers from the abuses that unofficial sellers have the potential to commit. Therefore, I can understand rules that has regarding these practices. I am not familiar with them specifically though so I do wonder how far they go.