I'm more interested in this part:
> you have a record of a lot of location/timestamp data for people
What is the source of that data?
I'm more interested in this part:
> you have a record of a lot of location/timestamp data for people
What is the source of that data?
from the parent post: `social media and/or ad data`
So if you have ad impression data you have IP geolocation, or maybe better, along with the timestamp. Similarly for socials sometimes you get location metadata, and with image uploads you can can get location metadata (though today these are often stripped, historically they weren't).