A couple thoughts:<p>1 - Market cap is (theoretically) the Net Present Value (NPV) of future cash flows.  You have to be careful about comparing this NPV (discounting forever) with a 1 year slice.  When interest rates are low, the future cash flows have a lot of value.<p>2 - Facebook&#x27;s value is likely based on other things too.  Advertising is just 1 way to monetize their users.  Imagine hijacking all of voice communications as an example.