I'd like to be able to use my C-Store points to purchase items for my friends - things I would never buy for myself, and that they would never pay money for, but which I am willing to buy for them.
Sound odd? Yes, but consider how many stores out there live off this type of sale... the entire concept of a "gag gift" is unthinkable if people only bought what they or their friends actually wanted, to say nothing of Christmas shopping and birthday gifts. And yes, I know you've had your eye on that Golden Tribble for a while...
It seems like a win-win situation, really:
Players get to buy gifts for their friends
Cryptic makes sales that they might not have otherwise
The only potential downside I can see is security-related:
Increased potential for damage if a security breach occurs (account hacked/stolen -> C-Store credits purchased using cached payment info -> Items "Gifted" to people via third-party site coordinated transactions)