Vodka, only vodka, my son (and parent post by Someone got an upvote from me too)
(This comment was brought to you by that one guy on the corner)
That's why they blast so much advertising even in place when the people are obviously already converted, they want to keep the status quo of them being the real cola, and the others being, well, cute alternatives but not the real thing. It seems to work, even the popular joke "pepsi, for when there is no coke" shows it. People in a restaurant don't ask "do you have a cola ?" they ask "I'll have a Coke" because obviously they have a cola and obviously it's Coke (which is funny since Pepsi rules b2bn while Coca Cola rules b2c).
So for Coca Cola, a victory is not for him to be out buying Coke right now, it's him thinking "Coke" when he should think "cola".