Wow. I understood very little of what you wrote above. It's like you're speaking a foreign language. I can write a TCP/IP stack in assembler, but thinking about ad networks hurts my brain.
All you really need to know is that when ad networks work, the first people to exploit are bad actors taking advantage of little competition. The networks need these guys to survive, so they tolerate it until they can afford to kick them out.
As the network matures, it kicks out the bad actors amd it becomes a healthy and effective medium for brands to communicate with consumers in a win-win-win way.