Political groups use “deeply spooky” protester location data, report finds
arstechnica.com
arstechnica.com
Yes, you can create an ad and set it up to target people live within a certain area or have visited a certain area (and/or a number of quite creepier feeling criteria), but that's it.
They are not "selling your data" to advertisers. As an advertiser, all you get is some statistics about who your ads got served to, and they are pretty shitty and vague.
"You said you were willing to pay $10.00 USD per click for people who have been within (LAT,LNG of XYZ hospital) within the last 30 days. We declare that 150 of the 200 ad clickers have indeed visited that location. That will be $1,500 USD plus some lesser amount for the other clickers that we somehow served your ad to. Let's call it $1700, we'll take it out of the prepaid account you had to set up before we even ran the campaign. Thanks for advertising with us, and if you don't like it, good luck finding another ad network with anything approaching the same exposure."
They set up an ad campaign in Facebook or Google or another similar network, and they have to decide who to "target."
Google and Facebook, and other networks to a much lesser extent and perhaps through other apps that people wouldn't expect to be related, have tremendous data troves about people.
This includes phone location data and history, and data from partners about things like what types of purchases a person makes on their credit cards, whether they are a homeowner and their home value, income... things like that.
All the advertisers actually get is the ability to say something along the lines of "This ad should show to people who were at or near X location and make less than X amount of money."
They don't "get" the data or have it "sold" to them. They are able to "use" the data in a very indirect way.