It might surprise you to know that SPAWNPOINT's owners - PHXX.com - was the FIRST EVER to launch in-game ads in CS/CSS.
Further - we didn't use VALVES code. We had our own. Sadly, we got the big o' cease-and-desist from Valve for doing so.
Check these links out
Link 1
Link 2
Link 3
If you recall the SUBWAY fiasco of 2 years ago.. that was us. We were paying for ALL Servers AND growing the network until Valve said we were not allowed to make money with their game.
So they off and did it on their own with our own marketing partner, IGA.
Joy