You guys are trashing this thing, but I have one and actually love it. I used it to get OFF of soda. I don't drink coffee so I used to drink a 2 liter of coke per day which packs on the calories. Tried coke zero, but I'm always concerned about those chemical sweeteners. So I use this thing to make plain seltzer water, and it works great. The 1 liter seltzers at the store are often $1 a piece, and I gotta lug them home. With this thing, I fill the bottle up at the tap which is ice cold, then put the bubbles in it, and i'm good to go. It doesnt go flat any quicker than anything store bought, but its irrelevant because the bottles are either half a liter or 1 liter and i drink the whole thing. When you do the math it comes down to about 25 cents a bottle. It isn't free, but its more convenient for me.
Is it better than cocacola? Prolly not. But it's cheaper and easier than seltzer water