This just smells like a bubble: "But this isn’t only about valuation, it’s about ego. At $25 billion, a Groupon IPO would nudge Google to become the largest venture-backed IPO ever. Yup, the same Google which offered to buy Groupon for only $6 billion last December as well. And that sounded crazy. An IPO at $25 billion would be as much about taking Google’s mantle as anything else."