@Teri_Kanefield depends on what you mean by that. It can undercount a bit because it depends on a JavaScript which some people block. Also people can reject cookies. But, assuming you’ve set it up correctly, it’s quite good. One thing to keep in mind is the complete data doesn’t show up until the next day. If you’re going beyond just things like pageviews, user sessions, and referrals, there’s a little bit of an “it depends” if you get either really high or really low traffic. Like if you are looking at physical location data for visitors and have low traffic, Google Analytics may not show it to you bcs it would be too easy to track info about an individual. You’d see a little caution triangle at the top of your report and when you hover it would say thresholding was applied.
But this is getting in the weeds. I’d say it’s generally quite accurate and very consistent so if you compare traffic from one time period to another to understand trends, you can trust it.
@Teri_Kanefield I’m happy to answer more specific questions. I don’t know much about how it interacts with advertising, but do know a bit about the use case for blogs.
@Teri_Kanefield One more thing, if you're comparing your GA numbers and site logs they might be very, very different especially if you're posting on Mastodon (as you are). My Netflify site logs show orders of magnitude more more pageviews than GA, because Netlify is counting every single hit, including, it appears, every time the site preview is loaded in Mastodon. GA tries to only capture actual people visiting your site. It can still be spoofed by bots impersonating people, but except during some kind of botting outbreak, I've found that to be uncommon. Your milage may vary with a more popular site.
@dys_morphia @Teri_Kanefield I used to run a very heavily trafficked site, and GA doesn't match site logs even if your site logs are filtered for non-bot pulls of main html pages. That's to be expected, because the GA javascript has to load after the actual page loads, and there are myriad reasons (as @dys_morphia has mentioned) that the main html can load and never load the GA elements or let Google know that your page was loaded.