I've done some research on this since Groupon doesn't release the redemption statistics. 20-30% breakage (non-redemption) seems to be the estimate, but some peo

I've done some research on this since Groupon doesn't release the redemption statistics. 20-30% breakage (non-redemption) seems to be the estimate, but some people go as low as 10% and as high as 40% in their estimates.