This sauna will buy back each gram of sweat you lose
A sauna in Osaka, Japan is in the middle of a "We'll buy back your sweat!" campaign. One yen per gram of sweat lost.
Spa Plaza, a sauna/bath house in Osaka, pays you for the sweat you lose sitting in their saunas. How this works is upon entering, you get on a scale in front of one of the attendants. They weigh you and keep a record of your weight. You then go soak in a bath, do what you do, and go sit in the sauna for however long you want. When you're ready to leave, you get yourself weighed again. One gram lost equals one yen paid back. The limit for how much you can be reimbursed is 3000 yen, about 30 dollars.
The folks at Spa Plaza predicted about an average of 200 grams lost in the sauna per person. But once money became part of the picture, many stayed in the sauna for as long as possible, with one man even losing 4000 grams. That's four kilos, or almost nine pounds! Since the limit is 3000, he only was given 3000 yen for his troubles.
This campaign goes on until the 21st. If I lived in Osaka, I'd be in the sauna as we speak, trying my best not to faint from dehydration.