This BBC article reports that a Berkshire bakery has nearly been run out of business by a overly “successful” Groupon deal. The owner, Rachel Brown, described these coupon sites well:

Without doubt, it was my worst ever business decision.

Groupon had this to say to the BBC:

We are actively engaged with all our partners at every stage.

Uh-huh. From now on this bakery will be known as that one bakery that almost went out of business, but stayed alive by cutting corners and bringing in unqualified labour. Though caveat emptor applies here, I reckon. Advertisers are buying an advertising service from the coupon sites, though it may not feel like it.