I agree Kev they'll do a runner sooner later what they are giving is 'what people want' high discounts off prices which may or may not be artificially inflated to make the deal look better, that deal has always been around I remember going to a large market and they had a stage where a guy was selling towels he had a microphone on and gained an audience quite quickly started his price high and then brought it down by may be 75% who knows what they were selling the towels in Asda the week before.
As UK consumers we are too greedy we want the deal and want the best, Groupon works better for both parties in the US as they want/like/expect to be upsold to we (UK) take offence at it.
The downside to groupon is that consumers will expect to pay what they see on their but in the real world also 70% discounts aren't real wasn't that long ago when I worked at Servicemaster the owner was sending reminder letters out offering 5% off and getting a good response!
Shaun
PS I had to slim this post down abit so not to get confused with a Jim Neal post