All you industry insiders should certainly read Rob Hahn’s most recent post that digs into whether Zillow is truly a company that will reach a $50 billion valuation.
I honestly have no idea what the long term valuation will be, but do have one word to add to the discussion:
I’ve traveled all over the place (while building Horizon / Oh Hey World), and generally look up real estate sites in the locations I visit. Let me tell you. They are mostly (not all) complete crap. I’d be willing to bet a pretty penny Zillow going into international markets is a matter of when, not if. There is lots and lots of money to be made outside the confines of the US that should factor into the long term valuation equation.