UTM tags are the little labels on the end of your links — utm_source, utm_medium, utm_campaign. They’re how every analytics tool knows where a visitor came from. And because anyone can add them freely, they’re where attribution quietly goes to die.
Here’s how it breaks. One person tags a campaign facebook, another uses FB, a third writes Facebook_Ads. Your reports now show three “channels” that are the same channel. The numbers are technically accurate and completely useless. Nobody notices until someone asks a simple question — “how much did Facebook make us?” — and there’s no clean answer.
The rule: decide once, enforce always
The fix isn’t clever, it’s strict. Agree the allowed values before anyone builds a link, and never deviate:
- source — the platform, lowercase, one spelling only:
google,facebook,linkedin. - medium — the type:
cpc,email,social,referral. A short, closed list. - campaign — a consistent pattern:
2026-q3-winter-promo. Date first, so they sort.
Lowercase everything (analytics tools are case-sensitive — Facebook and facebook are two channels). Ban spaces. Keep the whole convention on one page and make it the only way links get built.
It is the least exciting hour of work in marketing. It’s also the hour that decides whether every report you read for the next year is true or fiction. Boring, yes. Six-figure boring.