I remembered a mixergy interview with Andrew Mason, who said that Groupon's secret lies in their writing.

I duly subscribed to the list and unfortunately found it waffly and difficult to read. There is a thread on Quora about this.

I wondered if Groupon does any testing at all and Andrew doesn't claim to do so.

I think these ads are an extension of their smug copywriting. They'd have to do a lot better than this if they want to win hearts and minds.