Starbucks' chairman Howard Schultz recently told his top executives that they may be "watering down the Starbucks experience [and] soul."

If the Starbucks "experience" and "soul" have anything to do with coffee, Schultz may be right that books, CDs, movies, stuffed animals, and egg, bacon, and cheese sandwiches distract from that soulful experience. What's fascinating to me is how Starbucks has managed to display this diffused branding in the most public of places - on its coffee cups.

Starbucks' cups, of course, ...