Last month I joined a Dietbet in which I needed to lose 4% of my body weight (8.4 pounds) in 4 weeks and the final weigh in was today.
Before (210 pounds):
After (197.5 pounds):
I win! I lost 12.5 pounds in 4 weeks, thanks to lots of Kangoo, Tabata, and sticking to 1200 calories on non-workout days. So I get the $50 back that I bet, plus I get to split the pot with all of the other winners. I'm psyched! I will definitely join another Dietbet and am even considering starting my own.