TL;DR The OP is of the opinion that Groupon's (and the group buying sector's) bubble will burst. No facts I think. Groupon must be super-confident in themselve

TL;DR The OP is of the opinion that Groupon's (and the group buying sector's) bubble will burst. No facts I think. Groupon must be super-confident in themselves to turn down $6billion. I suspect they have some very good metrics that indicate they will continue to grow to a considerable extent to justify that decision. I doubt it was made on gut feeling or whim. Or without facts.