> If there were plenty of talented developers why are they paying such astronomical salaries?

Because Facebook (and Google, for that matter) discovered a money hose that is called online advertising, so they can be more liberal with the money they dole out. Also, SV tends to be expensive.

The amount of money your are paid does not necessarily mean you are the best and brightest, as much the HN/software types like to believe.

> Because Facebook (and Google, for that matter) discovered a money hose that is called online advertising

They are more generous because they have more money? Preposterous. That's not how businesses work. Businesses pay the lowest possible salaries regardless of how much money they make. If they are paying high salaries that's because that's what it takes to hire the top talent. The laws of supply and demand come into play here, not generosity.