@MozzerllaRick
This is NOT specific to SLR but a general answer for how most websites track your usage.
Browser stats are a powerful thing just about every website or web app you go to has some form of metrics enabled that allow them to gauge specific information about the users visiting a site. This can be things like total time spent on a site, click paths, conversions, unique users, button clicks, or feature usage. This is how a product team can tell if an new feature is being adopted, or if the average user only rewatched a video x number of times, or the average length of time a video is viewed before moving to the next one.
With these metrics if demographics is enabled then you can pair the above stats with things like location, age, gender, etc. (if you donāt think Amazon knows your porn preferences think again).
The demographic information is gathered from multiple sources. This could be 3rd party double click cookies, android advertising id, iOS Identifier for Advertisers (IDFA, just to name a few, but If you go to a site and login with a 3rd party auth like Amazon, apple, Facebook or google, thatās an easy way to get all info from your profile data thatās passed.
This is also the reason you see the āāacceptā or ādeclineā cookies on almost every site you go to now. The EU has GDPR rules in place that can heavily fine companies for tracking usersā PII (personally identifiable information) without their consent.
Hope this answers your question.