In this specific example, the restaurant does have a contract with the delivery service and they're still re-directing customers. Advertising, or trying to red

In this specific example, the restaurant does have a contract with the delivery service and they're still re-directing customers. Advertising, or trying to redirect to other restaurants paying higher commissions are the only possible explanation (aside from incompetence of course, but if you believe that I've got a bridge to sell you). They're trying to maximize revenue by double-dipping. They want the $70 food order and another $X because you viewed some ads.