[jasode]

>I'm sure they make TONS of money from ad revenue.

An old news article said they only get ~33% from banner ads. Most revenue comes from from job listings:

http://fortune.com/2015/01/20/stack-exchange-40-million/

[nicodjimenez]

Right, although I personally would consider job listings ads

[adrianratnapala]

True enough, but the details are different. And surely SO will have different internal departments and processes for managing each.