How Matomo stores the name
"Campaign values are stored in lowercase," Matomo's guide to building tracking URLs warns, and it advises against capital letters for that reason. The same guide says spaces often break links, so use underscores, hyphens or %20, and encode special characters, so a forward slash goes in as %2F. Pick one style and keep it: brand_awareness and brand-awareness display as two different campaigns, and the traffic splits between them.
Eight slots, two without a plugin
Matomo's own example link uses all eight mtm_ tags: mtm_campaign, mtm_source, mtm_medium, mtm_keyword, mtm_content, mtm_cid, mtm_group and mtm_placement. Out of the box, Matomo reads the campaign name and the keyword. Its URL builder says source, medium, content, campaign ID, group and placement each require Matomo's free Marketing Campaigns Reporting add-on, and group and placement also need Matomo 4. The website URL and campaign name are the only required fields.
When mtm_ and utm_ share a link
Matomo reads Google Analytics style utm_campaign tags too, so one link can carry both. Its rules for that case:
- The same field on both prefixes, such as
mtm_campaign=invest_webinar&utm_campaign=invest_tips: the mtm_ value wins, so the campaign is invest_webinar. - Different fields, such as mtm_campaign plus utm_source: Matomo uses each value.
- The same parameter twice: the first one in the URL wins.
That lets one URL report under one campaign name in Matomo and another in Google Analytics.
What a visitor gives away
The values sit in plain view in the address bar, which is why Matomo tells marketers to keep personal data out of them. Its example of what not to do ends in utm_content=john_smith. A normal mtm_campaign value holds a campaign name only, and the page does not change if you delete it. What goes is the campaign credit for that visit. The older spelling of the same tag has its own page at pk_campaign.