Getting the right deal from Groupon

As we reported last week Groupon is facing an investigation from the Office of Fair Trading on over 40 counts. On the face of it, it's been accused of over-egging its advertisements to both end customers and merchants. It's confirmed it wants to talk to the OFT about improving, and in fairness you have to say that if it's a case of the same mistake 40 or more times then it may not be as bad as it sounds - but how do you get a good deal from Groupon?