Comment by zaarn

Hi,

I might be able to help because I wrote an analytics tool a while back that tracks these three properties and some other stuff

1. Knowing which URLs are being visited allows me to see if a particular campaign or blog site is popular

2. The referrer tells me where a user came from, this is helpful to know if I'm being linked to reddit and should allocate more CPU cores from my host to the VMs responsible for a particular service

3. The screen size allows me to know what aspect ratios and sizes I should optimize for. My general rule is that any screen shape that can fit a 640x480 VGA screen without clipping should allow my website to be fully readable and usable.

4. I also track a trimmed down user agent; "Firefox", "Chrome", "IE", "Edge", "Safari" and other. All will include "(recent)" or "(old)" to indicate version and other will include the full user agent. This allows me to track what browsers people use and if people use outdated browsers ("(old)" usually means 1 year out of date, I try to adjust it regularly to keep the interval shorter)

5. Page Load Speed and Connection. This is a number in 10ms steps and a string that's either "Mobile" or "Wired", which uses a quick and dirty heuristic to evaluate based on if a connection is determined to be throttled, slow and a few other factors. Mobile means people use my website with devices that can't or shouldn't be drawing much bandwidth, Wired means I could go nuts. This allows me to adjust the size of my webpage to fit my userbase.

6. GeoIP: This is either "NAm", "SAm", "Eur", "Asi", "Chin", "OcA", "NAf", "SAf", "Ant" or "Other". I don't need to know more than the continent my users live on, it's good enough data. I track Chinese visitors separately since it interests me.

Overall the tool is fairly accurate and high performance + low bandwidth (a full analytics run takes 4KB of bandwidth including the script and POST request to the server). It doesn't collect any personal data and doesn't allow accurate tracking of any individual.

If I want to track high interest users, I collate some attributes together (Ie, Screen Size, User Agent, Continent) which gets me a rough enough picture of high interest stuff for what I care. You don't need to track specific user sessions, that stuff is covered under the GDPR and not necessary.

Before anyone asks if they could have this tool; nope. It's proprietary and mine. The code I've written for it isn't hard, very minimal and fast. I wrote all this over a weekend and I use influx + grafana for the output. You can do that too.

Both mine and the product of the HN post are likely not in the scope of the GDPR since no data is collected that can specifically identify a user.