Facebook hasn't yet really spent time on monetization. Their primary goal has been quick growth and they have greatly succeeded in that. Yes, there are ads and similar, but they are not yet at the level they could or even should be. Thus it's useless to try to compare to Facebook's earnings. And this is how the game is played, and what even many slashdotters want - make a great service first, and only then focus on profiting. It's not like Facebook is going to run out of cash, they still have great income and assloads of banks and venture capital ready to kick in if needed.
I do have to applaud Mark Zuckerberg. He is definitely a geek that made it, and at such an young age too. I know slashdotters are jealous and hate him, but boy is he something. He even shows the typical geeky attitude of wearing whatever clothes he wants, even to business meetings with banks! Give the guy some credit where due.