Running a joke into the ground

Several years ago, my good friend Bob (owner of greeting card store called Two Neat) and I collaborated on this greeting card: 

It’s a cheap joke but it was cracking us up. Bob decided to put it in his store to see if it would sell and, despite some people telling us we’re going to hell, it turned out to be a big hit. At that point, Bob did what any self-respecting retail genius would do: He made a “Stevie Wonder” card for every major and minor holiday: 

Happy Cinco de Mayo a day early! Stevie is raising his margarita glass to you. 

EDIT: I had an emergency appendectomy last week and Bob sent me this get-well card the other day. He's added another card to the Stevie line. This really made me laugh.