My answer: Take a look at the dotcom bubble, adjust nasdaq marketcap for inflation (and maybe much more because of ZIRP) and there you have your target market cap.
Yes, the only question is when the dumb money is in. I guess dotcom is here a historical precedent.
Since we cannot really know, I will just use that number and gradually sell around it. Of course that might make me the dumb money but that's a risk I'm willing to take.