The Vanishing Campaign Traffic
Your company runs paid search, display, and email campaigns, and your marketing team relies on a First Touch channel report to justify spend. Last quarter, the email channel showed 42,000 visits and 3,100 conversions. This quarter, email shows only 8,000 visits and 600 conversions, even though your email platform reports a 15% increase in clicks. Your display campaign's visits jumped from 20,000 to 58,000 in the same period. The paid search numbers are unchanged. A new tracking parameter was added to the display URLs at the start of the quarter: utm_medium=email-display. The email team says nothing changed on their side. The display team says they followed the documented naming convention.
1. What is the most likely cause of the email decline, and how would you confirm it before changing anything?
Read the worked answer
The display team's new utm_medium=email-display value is almost certainly being classified into the Email channel by a rule that matches on "email" (a contains/startswith rule), so display traffic is being misattributed to email. But email visits dropped rather than merely being diluted, which points to a second issue: the display traffic is now stealing first-touch credit from email visitors who later click an email. The display visits surge (20k→58k) and the email drop (42k→8k) are roughly inverse, which fits.
Confirm before acting:
- Pull a Marketing Channel report broken down by the raw
utm_mediumvalue (or the tracking code) to see exactly which medium strings are landing in the Email channel. - Check the Marketing Channel Processing Rules and their order - a broad "contains email" rule placed above the Display rule will capture
email-display. - Compare the email channel's visit count with and without the display medium to quantify the contamination.
- Verify whether the email drop is a first-touch effect only (check Last Touch and the email platform's click data side by side).
Do not edit rules until you have the raw medium breakdown; otherwise you cannot prove the cause or measure the fix.
2. The display team argues their naming is fine because it "contains email." How do you resolve the conflict, and what is the durable fix?
Read the worked answer
The naming convention is the root cause, not the rule alone. email-display is an ambiguous token that violates the spirit of a one-medium-per-campaign convention. The durable fix has two parts:
1. Fix the rule (immediate): Reorder or tighten the Marketing Channel Processing Rules so Display matches its own explicit medium value before any broad email rule, and change the email rule to an exact match on email rather than a contains match. Marketing Channel rules are not retroactive by default - confirm whether historical reprocessing is available and acceptable, and communicate that historical reports may shift.
2. Fix the convention (durable): Update the documented naming standard to forbid compound medium tokens and to require an approved value list. Add a validation step so new campaign URLs are checked against the list before launch.
Governance point: Because rules are ordered and first-match-wins, a loose rule high in the list silently overrides everything below it. The team should own a rule-order review whenever a new medium value is introduced.