There’s a documentary on Prime right now called Hot Money. Mostly it’s about how financial markets play games with bundles of debts.

To make an analogy:
Like a pre-leveraged loan, advertising starts small with the time and attention it steals from you when you make a purchase (they steal control of your identity), and when you read a billboard driving down the road. After that, the 'package' of the now greater than zero potential purchase or click is bundled with trillions of other non-zero potentials. Where direct-mail used to cost real money for postage and printing costs, emails cost almost zero. That mathematical difference gets churned through millions of times per second like the mining of Bitcoin, each time it’s generating more potential in the potential of selling the potential of that one identity becoming another advertising theft. Product is unnecessary, actually. Once you’re tagged, there’s really no untagging. Like pierced ears, you can take out the tag (unsubscribe), but there’s a hole in the control of your identity forever. They get a tax deduction for doing this. You don’t get paid back any more than you get paid to buy a car to drive to a job to buy a car.
You’re supposed to believe this is your freedom to choose.