How does one even collect the data from 300 trackers?

Your 300 affiliate marketing partners run software from their affiliate network which automatically analyzes their tracking pixel server logs to determine how far the traffic they steered made it through your purchase process based on the pixels they requested (unique for each page) and the unique ID in their cookies. Then, their affiliate network collects the sales commissions and pays out the affiliate partners.

Ah, gotcha, that makes more sense. I was like, 300 individual sites with individual tracking on what page, what the, how the, etc. Thanks for the clarification!