Yap. Especially in the case of Groupon, many of their articles read like poetry--very daring imagery and voice. They are doing as much service to the people who subscribe to their emails as to the brands who have the honor to get the Groupon face-lift.
It is a very refreshing model compared to most other startups where as far as I can see, paid no attention to copywriting.
Woot would be another example of a startup with great copy. I buy something like 0.5-1% of all Woots that I see - but I keep checking them because at least 20% of the descriptions make me "lol".
It is not just the copy, it is the whole direct selling layout. They know the tricks and the methods. Benefits, big buttons, ask for the order etc. Good job.
It is a very refreshing model compared to most other startups where as far as I can see, paid no attention to copywriting.