When you order a soft drink in an American restaurant, two things are assumed. One: you will get a drinking straw, wrapped and sealed in a paper tube. You are not required to lift a drinking glass to your lips in the United States. There is always a straw. And two, there will be free refills.
It's kind of disconcerting, sometimes, to be halfway through a glass of lemonade and then discover it has been taken away and replaced by a fresh one. Was there something wrong with the one I was drinking? Not all restaurants are quite that proactive. Most wait until you've actually finished the drink before replacing it, and some actually require you to ask for the refills. If a restaurant isn't going to provide free refills, it's usually for some specialty drink, like mango lemonade, and they write it on the menu. Usually the free refills are provided for pop, lemonade, iced tea and the like.
Some Canadian places offer free refills, but that will be written on the menu, probably highlighted. And those are probably American chains. I always wonder how many Americans visiting Canada ask for several refills of their Coca-Cola over the course of a meal and then are stunned to discover that they have been charged the full price of the drink each time. Of course they probably wouldn't drink them all, because they'd be still waiting for their straw.
So when statistics tell me that Americans drink 600 12-oz servings of soft drinks a year, I have to wonder how many of those they actually drank. I often get myself in trouble if I order a soft drink because they were a rare treat when I was kid, so I drink it all up, end up drinking two or three glasses, and then find I've filled up on sugar water and can't eat my main course.