[bluGill]

Because there are people who buy more than one of something.

Buy a widget - you might be purchasing for a company and will buy a the same widget next month for the next employee. If you advertise your widget to everybody 99.999% won't buy it, so that 99.9% that won't buy another widget is a much larger margin of those who will buy another. (the ad is about either keeping you a loyal customer or getting to to switch to a different brand). Most of us are more valuable as a possibly purchaser of more than one than as a potential customer of something new we didn't even know we needed.

[aeorgnoieang]

I read a related claim about this. People that just bought an, e.g. refrigerator, are much more likely than others to buy a second one soon as they're more likely to need a new refrigerator and even the small chance that the one they just bought doesn't work or isn't satisfactory means there's a much greater chance they'll need or want to buy a second one than that other people will want to buy one.

I could imagine buying a mattress would be an even better example.

[JumpCrisscross]

> Because there are people who buy more than one of something

The New York Times stopped behaviorally targeting in Europe without much consequence [1]. I don't think we can reject the hypothesis that adtech is largely a scam, with targeting being done more so adtech companies can "differentiate" themselves than for any benefit to publishers.

[1] https://digiday.com/media/gumgumtest-new-york-times-gdpr-cut...