I think this is probably correct. I wrote my own hit-tracker for my website and I spent a lot of time looking at logs to see if I could reliably track unique us

I think this is probably correct. I wrote my own hit-tracker for my website and I spent a lot of time looking at logs to see if I could reliably track unique users by hashing headers and the IP address. My conclusion is that you can't - you will always double count some users. It is no uncommon for consecutive requests from obviously the same user to come in from different IP addresses. Usually these are either cell phone users whose network changes from second to second, or browsers behind big proxies with multiple servers fetching content. For example, I would see this quite often (all fields made up): 75.34.234.71 index.html mobile-browser-v25 75.34.234.75 style.css mobile-browser-v25 75.34.234.75 header.jpg mobile-browser-v25 75.34.234.72 code.js mobile-browser-v25 Plausible would plausibly see that as 3 different users. Another problem is bots. So many bots. Some that take the trouble to mimic real browsers - they don't know they are bots. And they have a plan. Most bots don't bother to execute javascript but analytics that rely on single-pixel webbugs and the like will likely show inflated numbers.