For that matter, even if you wanted to do some evil psychographic ad thing, why would anyone sell that info to advertisers? What are they gonna do with it? Like

For that matter, even if you wanted to do some evil psychographic ad thing, why would anyone sell that info to advertisers? What are they gonna do with it? Like, why hand them the literal data, when you could allow them to just bid on ads that may be targeted/ranked using your painstakingly collected psychographic data (a la Cambridge Analytica)? Why sell cow when you can sell the milk? Because you don't have the platform. Not every company in data brokerage out there owns an advertising platform so that advertisers/ad networks can bid on ads. Furthermore, data isn't only about direct advertising. You can also analyze trends. See what influences purchases. Correlate purchase habits with news events or various other sociopolitical indices. Make your product better. Make new products. Find out which area is hip so you can open your new shop there, or buy some real estate. And the list goes on. Advertising is just the tip of the iceberg. You can exploit such data in myriads of ways.