I’ve never eaten a McRib sandwich, and suspect I never will. But even if you are like me (I guess particularly if you are like me), you want to read this very in-depth study of the economics of McRib availability.
[Edit: As the governor of Texas would say, oops. Updated with the actual link to the article (I meant to post this is as a linked list item, with the link in the title – but I hit the wrong button). Thanks, “isa”.]