I imagine there will be a charge at the Shake Shop just like there is for ice cream at the existing Coffee Bars. There is supposed to be some sort of Shake package that will be available.
" Shake Spot, the ideal place to “chill” where guests can enjoy delicious hand-crafted milkshakes while taking a break from all the fun in the sun. In addition to a distinctive island-inspired décor, Shake Spot will offer classic milkshakes and floats, as well as tropical fruit shakes and “adult shakes and floats” made with Grand Marnier, Cointreau and other liqueurs, all available with a variety of fun toppings. There’s even an all-inclusive “Shake Lover’s Package” for those who simply can’t get enough of these unique and nostalgic treats on vacation."
Carnival Cruise Lines News