I have noticed a significant discrepancy in campaign tracking (UTM parameters) between what Matomo tracks and what I measure on the server.
I’ve been using Matomo for several years, mainly for basic tracking functions. Occasionally, I also use campaign tracking and have often had the impression that something isn’t quite right with it. For example, I’ve felt that Matomo “forgets” old campaign tracking data (is this maybe a GDPR-related setting?).
Recently, I tracked an email campaign various times using UTM parameters. The numbers seemed extremely low to me.
So, I simply logged on the server side in a track.log whenever example.com/?utm=xyz was accessed.
Over the past two weeks, I logged 48 hits this way. Matomo, however, only shows me 6 visitors.
I know this might also include bots, for example. But the URL was only used in a tiny email campaign, so Google and others shouldn’t know about it.
How can this be? That’s a huge difference. When I access the URL myself, I am correctly counted in Matomo.
Do you think this discrepancy is normal? Can I test this further? Any ideas?
Matomo 5.3.2
Using the default Matomo JS tracking code