Multi Channel Conversion Attribution - models comparison

Hi all,

I’m checking the Multi-attribution report on Goal menu and I noticed that all models are returning me always the same numbers. When I try to compare Last Interaction and First Interaction models, the results are thesame on both:

Anyone knows why it is happening?

Thank you

As this concerns a Premium feature, I let @innocraft reply your interrogation…


actually I believe it is not an issue in this premium plug-in.
I’m look into it and I found a situation that I’m not sure if is a normal behavior of Matomo.

I simulate a visit in my website as a simple visitor (not a site member) just exploring the site. On the log table I can see this visit as well as all previous visit.

So far, Matomo gave me a new “idvisit”, the same “idvisitor” used in the previous visit and “user_id” is null because I’m not a member of the site. At this moment, the “idvisit” is 167992438 and the “idvisitor” is 3BF55B2601D45903.

So I signed-up the website to became a member and converted this specific goal. Checking the request sent to my Matomo instance I could confirm the “user_id” and “id visitor”.

However, when I double checked the log table, I noticed the “idvisitor” had changed. Now the “idvisitor” is 30E9950509760CC5.

Is it a normal behavior from Matomo when an “user_id” is assigned to a visitor?
I don’t believe it is a normal behavior, because this way the Matomo is losing the link with previous visits of this visitor/user.

thank you

Just as additional information, the new “idvisitor” was assigned just to the current visit.
the previous visits kept the same idvisitor as before visitor became a user/member.

Thank you

Still looking at this.

Does the following help?

" When a visitor connects to your website but is not initially logged in, their visit is associated with a Visitor ID by default. This is a unique identifier for that specific visit that is not attributed to a specific user. However, once that user logs into their account and you set a User ID for this visitor, then all actions such as page views are linked to the User ID and not the visitor ID. Any previously tracked action for this visitor before the user was logged in is also associated with this User ID.

When a user logs in, Matomo counts all actions before and after logging in as one user, one visit, and one unique visitor."

From the docs (

What is your configuration of (in config.ini.php file):



I’m using the default one: enable_userid_overwrites_visitorid = 1

My Matomo instance is working like this if visitor is already a member of the site and he is just log out. Once the user logs in, this current “idvisitor” is replaced to match the “idvisitor” related to the User_ID.

But it is not happening if a visitor is not a member of the site (has no User_id), and did several visits before become member. When this visitor join the site and become a member (now he gets a user_id), a new idvisitor is assigned to this new user_id just in this current visit when he became a member. All previous visits from this new user is not receiving the new id visitor.

So, Matomo is not keeping the link between the visits before and after a visitor becomes a user and that is why the Multichannel Attribution report has the same result for ant model in case of a Join conversion goal.

Thank you

hey @Genest and @heurteph-ei

did you have a chance to look further into this issue?

I’m still having problems to track previous visits from new users on my site and I don’t know if there is a work around for it. I have updated Matomo to version 4.10.1 and the behavior is still the same.

Please let me know if you have any additional information.

Thank you

As previously said @Genest , the visitor ID is updated with the user ID when provided during the visit (even if not provided at the first page view). But this behavior works well for a visit, not for the whole user history.
I think you may create a feature request in the Matomo GitHub in order to take the previous visits into account:

HI @heurteph-ei ,
I appreciate your quick answer!
However, in my point of view, this case should not be a new feature. I believe Matomo should update the visitor ID for all visits from an user to keep the accuracy of the entire user’s visits history. Otherwise, it will directly affect an important report as Multi Channel Conversion Attribute for goal as “Sign Up”. As you can see in the screenshot of my first post, the First interaction and Last Interaction metrics of the Multi Channel Attribution repost are the same because the system lost the visits history once the Visitor ID was updated just in the visit where the visitor signed up in the site.

Please let me know if it makes sense. I’m not sure if I was clear enough in this explanation because English is not my first language.

Thank you

Hi @ograssini
This is clear for me…
In my last message I used “feature request” as a generic term for new feature or bug report… (and the link I provided was for bugs).
In GitHub, there is already some (other) bug/feature about conversion attribution:

Your one is another use case I think.

Ping to @SteveG who participate the most on this subject.

@ograssini It’s not possible to simply update the visitor id for older visits.
Nevertheless I think your problem is more related to the user id feature than to conversion attribution.
If setting the userid creates new visits, where it shouldn’t, changing the config flag enable_userid_overwrites_visitorid might help you.

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