Before Deleting an Old Ad Unit: A Short Checklist

I retired an old ad unit last spring and assumed the work was done when it disappeared from the dashboard. Two weeks later a colleague sent me a screenshot: the slot was still rendering on a campaign template I never searched. That mistake cost me an afternoon and taught me to slow down before deleting anything.

Here’s the checklist I use now.

1. Record the unit’s exact name and ID in a plain text file, plus the date and the reason for retiring it.
2. Search every template and codebase for that ID, the display name, and any wrapper class or lazy-load rule tied to it.
3. Archive the last 60 days of reports before you change anything, including impressions, clicks, and revenue if available.
4. Check the last few days of impressions to confirm the unit is actually idle; a trickle of traffic usually means a forgotten placement.
5. Remove the ad tag, then remove the surrounding container, CSS, and configuration references, and test on staging.

The naming part matters more than it sounds. If the unit is called “sidebar_300x250” and there are three similar names, I write down which one I mean and where I found it. I also note the network and placement so a future me can follow the trail.

For the report archive, I save a CSV and a short note explaining why the numbers dropped to zero. That way, when someone asks six months later, I don’t have to guess.

I keep my own ad unit cleanup checklist next to those exports, and I verify the provider’s current instructions before I remove the final tag: ad unit cleanup checklist. The last step is always a quiet check a week later — search once more for the ID, confirm no stray impressions, and then let the old unit go.

— Daniel Hayes