Hrm, maybe. I think social/casual gaming with virtual goods are here to stay (they've been growing like crazy in asian countries for years and years). Groupon isn't particularly defensible, but the model seems to scale infinitely, and restaurants.com has been doing it with less splash for years. Groupon's 50% margins will get trimmed over time and certain types of merchants will realize that it's a pile of fail for their business... But why won't Groupon and it's ilk always be a great deal for businesses like restaurants and spas (especially if they start allowing for blackouts on weekends?).

I'd agree that groupon (unless their CEO's statements are to be trusted) is not entirely sustainable, but i don't think they are going to disappear completely. Additionally I don't think social gaming is going to go away either. It might look completely different as browsers, and users evolve, but its going to be here for a while. There is always going to be a social platform, and right now its facebook.

Pets and toys never went out of style either, but that didn't stop bubbly companies specializing in each from blowing up. I think Zynga is better positioned, but they are a very shady company and that makes me pause. It feels like a pump with VC and dump to IPO like the dot com era gave us.