Ah, that makes more sense. Thanks for clarifying. I'm still not so sure it's true though. Is it materially different to go buy from 5 ad brokers instead of 1

Ah, that makes more sense. Thanks for clarifying. I'm still not so sure it's true though. Is it materially different to go buy from 5 ad brokers instead of 1? Or from ad exchanges that automate it for your? It's hard for me to see how this would have much of an effect, beyond mildly increasing the cost.