I would like to know how many sodastream users have refilled their proprietary co2 canisters more than twice.
FWIW, if you're really looking to save on soda, you can put together a DIY fountain setup with a real CO2 canister that you can refill at a welding shop for a fraction of the price of the sodastream gizmo and then buy bulk syrup for a fraction of the price of sodastream syrup and it's the real shit (Coke, Pepsi, etc). Enough Syrup to make 30 gallons of Coke is like
$75 at Sam's Club. You can fill a 5 lb c02 canister for $15 which will last almost forever vs. the same price for a 15 ounce Sodastream refill.
How To Make Your Own Home Drink Carbonation System | Popular Science