It doesn't work like that is what I'm saying. You dont just pitch those companies. They have layers of agencies (a master agency of record, creative agencies, media buying agencies) that handle all the advertising duties. These shops create and traffic these ad campaigns in demand-side platforms (DSPs) which connect and bid on inventory in adexchanges and supply-side platforms (SSPs).

Then there's layers of targeting, accountability, measurement, and insurance that gets requested and bought from anti-fraud, brand-safety and verification vendors. That's likely where this fingerprinting came script came from.

Going to individual agencies with your own different supply path is not going to get any attention and nobody is going to change the way they buy millions in advertising just for you. No single publisher has that much power these days, not even Stackoverflow.