Some credit card companies offer a cash bonus for store purchases.
Let's say Mincha has a live-in Gentile worker, Jim. Jim is an authorized credit card user for Mincha's account. During Pesach, Jim buys lots of chametz and charges it.
In June, Chase bank, gives Mincha $200 in cash back bonus for all the chametz that Jim bought several months ago.
Even though Mincha didn't get the bonus immediately during Pesach, did he derive any benefit from the chametz that, he paid for?