I have sailed on the Dawn last year and the Sea 2 years ago. Both offered soda cards, price was around $29 for a seven day cruise. When you buy it, you'll probably get a container of some sort (for the soda) and a sticker for your room key. Although they may say you need the container to get refills, you really just have to show the sticker on your room key. If they ask, tell them you forgot the container in your cabin, and they'll serve you a refill in a plastic glass. Hope this helps.