Soda Pop is not free. I bought a soda card on my second cruise thinking that I could save money. It may have if I had used it enough. After the cruise I realized that I did not drink enough to make it pay for itself. I also found that several of the bars fountain drinks tasted flat. This was not the same every day, it was a crap shoot.
No soda is not free. It is usually $1.50-$1.75 per can plus 15% gratuity. A soda package is where for one set price you get unlimited soda for the length of your cruise. The price varies depending on the length of your cruise. A seven day cruise is about $29.95.
Juice is free on the buffet in the morning, in the dining rooms, and you can find it free on some of the drink stations. Usually in the afternoon it's hard to find juice, ice tea and lemonade take its place on most of the drink stations. Coffee and tea are always available for free, as well as non-bottled water. Bon Voyage
Soda cards are for fountain soda only. As mentioned earlier...lots of problems with flat soda. On a recent cruise we purchased water and soda at the supermarket on the way to the pier. Checked them at the curb (cabin number on each) and they arrived in the cabin fine.
I think a lot of people who buy the soda cards don't consume enough to make it a value.
If you need juice all the time...buy some before you board the ship.
Regal Princess 1996
Sun Princess 1998
Grand Princess 2000
Ocean Princess 2001
Golden Princess 2004
Caribbeean Princess 2004
Caribbean Princess 2006
We bought three of the soda packages (myself and children) and didn't get our money's worth. We were off the ship more than we were on it, so ended up buying something to drink during the day at the ports. Drinks came with our meals. It was nice having so I didn't have to worry about my kids running up a "bar tab." The mug was a nice souvenir.
On every Carnival cruise we've taken since 2003 they have abandoned the use of fountain soda. All soda comes from cans, even that for the soda cards. Of course, it is not a full can per serving when using the card - more like half a can or less. I simply cannot endorse adults buying the soda card. For kids it is the convenience, even if you don't end up getting your money's worth in product.
My son has also used his card to get more than soda. He likes Carnival's fruit punch, which is made by the bartenders (orange juice, pineapple juice, grenadine, and whiskey sour mix). He has always been able to get this without incurring an extra charge. It may have to do with my familiarity with the bartenders!