You're making one very big assumption, which is that professional and well informed investors would not want any part in it if they knew it wasn't a sustainable business model.
They might know better than we do when this thing is going to blow up. Or they might have an idea for a transition to a more sustainable business model once Groupon has reached ubiquity.
Right now it looks to me like they have misjudged how quickly opinions would turn against Groupon's business model or rather against their accounting practices. An SEC investigation isn't something any investor, no matter how professional and knowledgeable, wants or expects to see.
They might know better than we do when this thing is going to blow up. Or they might have an idea for a transition to a more sustainable business model once Groupon has reached ubiquity.
Right now it looks to me like they have misjudged how quickly opinions would turn against Groupon's business model or rather against their accounting practices. An SEC investigation isn't something any investor, no matter how professional and knowledgeable, wants or expects to see.