Monetisation & Revenue
Programmatic Advertising
Also called: programmatic, automated ad buying
A buyer sets a budget, an audience and a target, and software bids for each impression as it comes up. No salesperson, no signed order, nobody choosing your video. Most of what runs before and during a YouTube upload arrives this way.
It explains why RPM swings by season and by topic while you change nothing, since the auction tracks what advertisers will currently pay to reach the people watching. It also draws the line against a brand deal, where the price is one you set yourself.