A soda card gets you unlimited soft drinks for approx $6 per day,plus 15% tax. Only snag is they have diet coke/pepsi but I never saw diet lemonade or tonic. It is worth it if you drink more than 3 or 4 glasses a day, but remember that on some cruises you are off the ship most of the day.
Thank you for your info Sutton. Do we purchase the card on board If not then where?
You purchase it at any bar once on board. It is just a sticker that they put on your card. on RCL you don't even sign for your drink but I can't remember definately that it was the same with Princess.