Obviously eBay thought that the traffic is compliant. They didn't know that this was just cookie stuffing and that the sales they were paying to him for would happen anyway. When his affiliate sales declined, affiliate manager would of course be worried and try to re-engage the affiliate. But how stupid eBay affiliate managers could be if they didn't notice that actual sales volume was the same whether with his traffic or without. Well, maybe not completely stupid after all, if they finally had some grey matter to realise something fishy (and so simple) was going on..