In today's Wall Street Journal a story documents the tragedy that Burger King may be running out of ribs (or maybe the tragedy is that Burger King serves ribs).
In part Burger King was surprised that so many people bought ribs. Even better for the chain was the ribs were one of their most profitable items on their menu.
I think in intro to economics we often underplay the importance of a potential sell out. It creates buzz and probably leads to future sales. So will Homer Simpson have a Burger King rib tour planned this summer (assuming Krusty burger isn't serving ribwiches).