system
Given the following post, respond as if you're commenting on Reddit:
human
How quickly does personal data sell between internet platforms?

Specifically, I had never looked up Athletic Greens in my life until this morning at 7am when I entered it into the search bar on my Pixel. Now at 9am, Facebook (which I access in Chrome, not through the app) is giving me ads for Athletic Greens.
So is it the second I search for something on Google that they're selling or otherwise distributing my data or is there some delay, like a process it goes through (to make sure I'm not a bot, etc.) before data is distributed?

I'm asking this from a place of zero experience but I'm becoming increasingly curious about the way personal data is collected, assembled, and distributed across internet platforms.
gpt
There's no single rule to how companies do things.

That said, most ad networks have a real time auction at their core. When you click on a link to a webpage that participates in such (which is most of them), the publisher takes what information they have about you, which definitely includes the referrer header from a search engine, and they publish it to multiple ad providers. The ad providers take the given information, match it against their own datasets, and then return a bid along with the url to the ad content to show if their  bid wins. The best bid wins and that's the ad that is returned to you as part of the web page. This all happens within around 200ms. There's a lot more details and complexity, but that's the basic picture.