I've recently discovered Bounts, which rewards you for working out. You get points, convertible into vouchers (amazon, one4all, ticketmaster, supermarkets etc), for exercise. Points are earned by tracking activities through mapmyfitness, strava, garmin, swimtag etc, logging steps through jawbone, fitbit etc and checking in at participating gyms, tennis clubs etc.
Basic membership is free, but you can pay £10 or £15 a year, to get more points per activity. (As far as I can tell it is never economical to pay £10 a year, because £15 a year gets you twice as many points for the same activity levels.) Based on my activity levels I reckon I should make about £70 a year for the £15 subscription. I've been using it since the beginning of July and almost have enough points to order my second £10 voucher. More info is on the website: bounts.it/
If you use my referral code (fosberry5) when you sign up, we both get bonus points once you log your first activity.
It is fairly new and they have had some teething problems but overall it works and I love getting free money - these opportunities are so rare, and I thought you might enjoy free money too!
I think it is a really interesting way to motivate people to work out more. It totally works on me - not that I don't work out, but if I'm cycling back from the pool I will take a longer route to make the minimum 20 minutes duration to get points! (maybe I need to get out more?!) It also seems to be constantly developing and growing, eg swimtag has been added recently and if fitbit will provide Bounts with the info about your recorded workout then they will give points for those as well.
If you have any questions about how it works or anything I'm happy to help where I can. One of my questions that I couldn't find answered on the website was how it is funded, so I emailed them to ask - apparently it is funded by venues that pay to be listed to encourage people to go.
Sorry for the rambly post! Happy exercising!