TPE #140: Should you remove exclusion lists? (Real test results)

GM, Miles here with an interesting test result from Bob.

Lately, there’s been a lot of talk of people removing their (mature) exclusion lists from their Google Ads campaigns.

I originally saw the conversation getting started by ​Andrew Lolk​ on LinkedIn:

The idea is that over time, you might over-exclude by adding too many negatives and therefore restrict the algorithm.

Some say that Google Ads don’t need any exclusions at all, because Smart Bidding has evolved, and it knows better.

While we fully understand the concept, we always experiment first and let the data speak for itself.

So, Bob ran a 2.5-month experiment within all Search campaigns for a Lead Gen client.

I’ll share the (not so) surprising outcomes below.

Let’s dive in!

The setup: delinking all exclusion lists.

A quick note: the reason why Bob wanted to run this test is because he already managed this account for 7 years. He wanted to check whether or not he was limiting his account with (wrong) exclusions that he had added in his earlier years.

Here's the test setup:

• ✅ Removed all exclusion lists (yep, every single one)
• 🔎 Campaign type: all Search campaigns
• 📅 Experiment period: June 23 – August 31, 2025 (excl ramp-up)
• 📊 Metrics: conv. by time (due to conv. lags up to 22 days)
• 🧪 Comparison: Variant vs. Base

Campaign-level results.

Firstly, here’s the complete data from the test (interpretation below):

Secondly, interpretation of the raw data:

So, out of the 4 main campaigns tested:

• ✅ 1 performed slightly better in click-time conversions (but was neutral in conv.-time).
• ❌ 3 lost, and not just a little:
  • Lower conversions
  • Much higher CPAs
  • Significantly worse efficiency

The full summary in one line: business outcomes clearly worsened when Bob removed the exclusion lists.

Decision: Bob is keeping his exclusion lists because removing them did not deliver efficiency improvements — it even worsens outcomes under conv. by time attribution.

The final verdict: exclusions still matter (but it depends as always).

If you know how to add negatives correctly, they absolutely help Smart Bidding and improve efficiency by forcing the algorithm to focus on high-intent, high-quality traffic. That’s what happened in this case.

But...

If you're inheriting accounts, or don’t know the full exclusion history, there’s a decent chance your lists might be hurting performance. Especially if they've been stacked (too) aggressively over time.

In those cases, a reassessment is 100% valid.

One of the members of The PPC Hub recently ran the same experiment and saw a small uplift in performance after removing 95% of his negative keywords. That’s why it’s so important to test for yourself.

A lot of specialists are excluding the wrong way — and that’s why you see people getting better results after delinking.

But it doesn’t mean that all exclusions are bad. Or that automation always knows best.

In the end, what really matters is the quality of your exclusions.

Don’t just follow the trend of removing exclusions lists “because Smart Bidding knows better.”

Test it. Validate it. Let the data decide.

And if you're unsure, start by cross-checking your converting search terms with your exclusion lists. You might be shocked at what you're blocking — and that’s an easy fix.

(Bob used Claude to do this with some quick n-gram matching — worked like a charm.)

Quick recap:

• Removing exclusion lists hurt performance in our real-world test.
• Don’t assume the algorithm knows best — exclusions still play a critical role when used correctly.
• But… always reassess if you’re working with older campaigns. Bad exclusions can silently kill your results.

PS… Want more stuff like this?

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This breakdown was first shared with our members — along with tons of other exclusive tests, frameworks, and behind-the-scenes insights you won’t find anywhere else.

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• Deep-dive Google Ads experiments (like this one).
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Whether you're running ads for clients or scaling in-house, The PPC Hub is your unfair advantage in today’s Google Ads landscape.

Join us here — see you inside!

And that’s all for today.

Thanks for reading — catch you next week!

Cheers,

Miles (& Bob)