There have been liquidity events before, which allowed old enough employees to sell shares. You will find that many a former employee has managed to leave while being able to exercise their options and have a partial cash out with a lot of money to spare. So it’s not been an exercise of keeping employees tied down. A visibility one is Will Larson: You bet that he didn’t leave without being able to sell shares to cover AMT, and getting some immediate payout.

As for why stay private, what John C has said publicly is that they still see a lot of growth to go, and that not having to provide detailed financian statements to the general public, which would include competitors, is a competitive advantage. It seems believable to me.