UTM taxonomy, in practice.

Short, specific pieces on how UTM tracking actually breaks — and what fixes it.

• September 21, 2026

  Not every team has server-side GTM. Link Builder is for what happens before that.

  Inflight corrects a UTM value after it lands, inside a server-side GTM container. Link Builder validates it before it's ever built, no server-side GTM required, unlimited and free on every plan.

• September 15, 2026

  Pinterest starts writing its own UTMs on September 15, into fields you already own

  Pinterest is auto-appending utm_source, utm_medium, utm_campaign, and utm_content to ad destination URLs, opt-out only, with no API control at launch. Unlike a gclid, it lands directly in the taxonomy fields the rest of your stack already tags by hand.

• August 31, 2026

  GA4 shipped a fix for messy source data. Here's what it doesn't reach.

  Source Group, GA4's new reporting dimension, cleans up the biggest platforms at the report level. It doesn't touch the underlying data, your own custom sources, or anything outside GA4, which is exactly the part that's left.

• August 24, 2026

  The typo tax: what a misspelled utm_source actually costs you

  A single typo in utm_source doesn't lose data; it splits one real campaign into several smaller, weaker-looking ones. The cost shows up in the decision it changes, not in a missing number.

• August 17, 2026

  Auto-tagging vs. manual UTMs: the tradeoff nobody explains well

  Google Ads already tags your clicks with a gclid automatically. Adding manual UTMs on top isn't redundant; it can quietly work against the tagging you already have.

• August 10, 2026

  What GA4 actually does with a utm_medium value it's never seen before

  GA4 doesn't reject an unexpected utm_medium; it just can't place it in a channel group. The session isn't lost, but it does land somewhere far less useful.

• August 3, 2026

  Two links, one campaign, no way to tell them apart

  utm_content exists to separate two nearly-identical links. It's the UTM parameter most often left blank, right up until someone needs the answer it was built to give.

• July 27, 2026

  "Facebook" vs "facebook" vs "faceboook": GA4 doesn't know they're the same campaign

  GA4 treats utm_source as an exact string, not a category. A casing difference or a typo doesn't get corrected; it becomes a second, smaller campaign in your reports.