Why can't Sprite make a caffeinated version?

Before I begin, I should explain for those of you whodon't live in the South that Coke is the collective noun for all carbonated beverages. A typical exchange at a home in Mississippi would go like this:

Host: Would you like anything to drink?
Guest: Do you have any Coke?
Host: We have Diet Coke, Sprite, and Orange Soda.
Guest: I'll have a Sprite.

See how it works?

Now anyway, here's what happened to me today. I was really tired today in school, almost fell asleep in class (gasp), so I went searching for some caffeine. Coffee wasn't available at 2:00pm, so I had to settle for a Coke, which I rarely drink. I'm more of a water and juice girl, but that's not much of a pick-me-up. For the record, the only kinds of Coke that I like are either clear or fruit flavored. (Oh and Barq's root beer makes a red creme and vanilla flavor, they are great, but only found on the coast I think.) I really wanted a Sprite, but Sprite doesn't have caffeine, so I went to the Pepsi machine for a 7up. Do 7ups have caffeine? I couldn't remember, and still don't. Well, I click on the 7up button and a freaking Sierra Mist pops out. And guess what. It has no caffeine! I drank it anyway, and promptly almost fell asleep in class again. Why can't Sprite make a caffeinated version? I would stockpile it.