Definition
A campaign link carries, after the question mark, parameters that Google Analytics 4 reads on arrival: utm_source (where the click comes from), utm_medium (the type of channel, such as email, cpc or social) and utm_campaign (the name of the operation), then six others, including utm_id, utm_content and utm_term. GA4 recognises nine; two of them, utm_creative_format and utm_marketing_tactic, are not yet shown in its reports.
For Google Ads, auto-tagging (gclid) does this job: when a gclid and UTM parameters appear on the same address, GA4 credits the visit based on the gclid.
Value for a business owner
Without parameters, a visit from a newsletter or a LinkedIn post often arrives as direct or referral traffic, and the campaign gets no credit for the enquiries it produced. With a written convention, reports compare channels on the same basis.
At Stratedge Consulting
Our free UTM link builder builds links following GA4's rules and flags what would distort the reports. The CRMs we deliver can store these parameters with each enquiry, to connect the campaign to the sale.
Common mistakes
Writing the same source three ways (Newsletter, newsletter, NL): reports split the campaign across three rows.
Adding UTM parameters to auto-tagged Google Ads campaigns: GA4 keeps the gclid, and the parameters only show in the manual dimensions.