I've seen this question numerous times here. Judging by this Starbucks must have one of the most successful giftcard campaigns of all time!

I do enjoy Starbucks coffee, and it just so happens I have a GC in my wallet
However, the number of times I've craved a hot drink at WDW??? Nearly never

I know they have other stuff too, but there are other choices for cold soft drinks at WDW.