Analogy time: would you call someone who has $1bn someone who "gets" hard work, perseverance and financial savvy because they won the lottery (editors note: the author is not comparing Facebook's success to winning The Powerball
per se), based only on the notion that they have a surplus of money in the bank?
Let's move away from the lottery for a minute, but keep our handsomely wealthy hypothetical person in the picture. You meet Bob. Bob shows you a bank statement with $1bn on the balance line. Bob tells you his business is doing great and he's living his dream.
I will put down 1/7 of my next paycheck that the very first question you ask Bob is: "What's your business" or some variant thereof.
The point: Bob has a lot of money and you want to find out what he did that 'got' him the money, right? He networked, he made a product, he refined the product, he took his product to market-eliminating what worked, building upon, refining and reproducing what does. Those are the indicators you look at.
Simply having the users doesn't tell you a whole lot, or have we already forgotten the tale of MySpace (or Xanga, or Friendster)? I maintain it's how Facebook got and kept those users that matter to Facebook 'getting' social.