In the post they say each voucher cost them $8. So it costs them $11 to serve up a coffee and cookie they sell for $13. At $2 profit per sale they are going to

In the post they say each voucher cost them $8. So it costs them $11 to serve up a coffee and cookie they sell for $13. At $2 profit per sale they are going to need each and every voucher holder to make four additional purchases just to break even. Seems like this was doomed from the start. I think the real problem here is that the small business owner thought Groupon was working for them. They didn't realise that they're the ones being sold the product.