GSK$/$Pfizer has seen a nice increase in Advil sales. The brand manager has provided a lower bulk cost to retailers, so retailers are pretty happy. Now, the category manager for GSK$/$Pfizer products tells the brand manager, $$go talk with the category buyer at Kroger Stores; I think this is a good time for a tying contract for two of our new nutritional products.$$ This remark suggests that Advil is a: