I don't understand how the owner was not able to see this coming, you are offering $12 of product for a gross of $3 to you. Groupon lets you set maximum amounts of coupons sold... did she assume many people would not use these?
Recently a supermarket offered a Groupon for $40 for $20 and it sold out at $1,000. This promotion essentially cost them $20k... surely there is a better way to get customers for $20k?