hi all, we ran a promotion on reddit recently and gave away lots of promo codes, but ran into two issues: (1) people took more than one (2) users had to go through many codes before finding a valid one as a result, we had to roll our own service for distributing digital coupons that addressed these two issues. it was pretty annoying to do. some free service must exist. codehookup only works for promo codes and not proprietary IAP codes like ours. we just didn't have time to research this properly until now. what services do you use? thanks!