I always wondered what happened to Mr. Pibb. Now I know thanks to this explanation by Coca-Cola:
Mr. Pibb was launched in Texas and quickly expanded through much of the U.S. Mr. Pibb appeals to 12-to-15 year olds who are just gaining independence from home and looking for things to call their own. Mr. Pibb enables them to have an uninhibited, fun and unconventional attitude because it has the sweet, refreshing bold taste they need to express their independence.
Ah yes, the 12-to-15 year olds certainly need a sweet, refreshing, bold taste to express their independence. And not to mention their need for zit cream and a healthy injection of self-esteem.