AI Max turned on: new demand or rerouted exact match? (audit it before the upgrade)
Chinmay Raibagkar · reads the search terms report before the AI Max summary card🔀 with a query-source split, not a lecturePublished October 4, 2026
The 60-second version
- AI Max labels every conversion it touches, including ones your exact and phrase keywords would have won anyway.
- Split its queries into rerouted, new and irrelevant using your search terms history — only the new bucket is extra money.
- The fix: judge it on incremental CPA, fence brand, negate junk, and promote winning new terms to keywords.
Four weeks after AI Max was switched on, the Google Ads summary card looks great: 140 conversions from AI Max. The account manager screenshots it for the weekly update.
Then someone checks the account totals. Before AI Max: ₹4,00,000 spent, 500 conversions. After: ₹4,80,000 spent, 560 conversions. The account gained 60 conversions, not 140 — and paid ₹80,000 for them.
Where did the other 80 come from? From queries your exact and phrase keywords were already winning. AI Max matched them first and took the credit. same buyers, new label AI Max can find real new demand. It can also quietly reroute demand you already owned. Which one you're getting is the only question that matters before Google's upgrade deadline turns it on for everyone.
Four weeks before vs after AI Max
What AI Max actually switches on
AI Max for Search is not a new campaign type. It is a bundle of automation you turn on inside an existing Search campaign. Google is replacing Dynamic Search Ads with it; automatic upgrades were planned from September 2026, with the deadline later pushed to February 2027.
Search term matching
Shows your ads on searches beyond your keyword list, using your keywords, ads and landing pages as clues. This is where most new traffic — and most rerouting — comes from.
Text customisation
Writes headlines and descriptions from your site and existing ads, tailored to each search. Check them: they can promise things your page doesn't.
Final URL expansion
Sends people to whichever page of your site seems most relevant. Exclude pages like careers, blogs and out-of-stock categories.
Independent studies show why an audit is needed. An analysis of more than 250 retail campaigns by Smarter Ecommerce found a median revenue lift of about 13% — but a median CPA rise of about 16%, with ROAS outcomes ranging from +42% to −35%. A separate analysis published in July 2026 found more than a quarter of exact-match keyword impressions in AI Max ecommerce campaigns were no longer being served as exact matches. Your account could land anywhere in that range.
Three kinds of AI Max traffic
Everything AI Max matches falls into one of three buckets. Only one of them is new money.
Total account spend rose by ₹80,000 — the new and irrelevant buckets. The ₹70,000 rerouted bucket replaced keyword spend that was already happening, often at a higher cost per click.
The summary card counts every AI Max conversion as an AI Max win. It cannot know a conversion would have happened through your exact keyword anyway. Never judge AI Max on its own labelled conversions — judge it on what changed in the account as a whole.
How to sort a query into a bucket:
- Rerouted: in the 8 weeks before AI Max, the same search term got clicks through one of your keywords.
- New: the term never appeared in your search terms report before, and it is relevant to what you sell.
- Irrelevant: jobs, free, DIY, competitor support pages, wrong product — add as negatives.
Judge it on incremental CPA
Blended CPA mixes old conversions with new ones, so a bad expansion hides inside a good average. Incremental CPA asks a cleaner question: for the extra money we spent, what did we get?
New conversions cost well over target. Add brand and keyword fences, negative lists and URL exclusions, then measure again.
Before-vs-after is a rough read. Seasonality, budget changes and competitors move numbers too. Where you can, run AI Max as a campaign experiment with a 50/50 split, and compare the two arms over the same weeks. Wait for conversion lag to settle before you call it.
The query-source split in SQL
This sorts every AI Max search term into rerouted, new or irrelevant, using your search terms history. The irrelevant list starts with a few obvious words; grow it from your own negatives.
If the rerouted bucket is large and its cost per click is higher than your keywords paid for the same terms, AI Max is charging you more for traffic you already had.
Keep, fence or switch off
The AI Max decision
Process FlowMeasure incremental CPA, not the summary card
Use an experiment or a clean before-vs-after. If conversions didn't rise, switch search term matching off and stop here.
Fence the brand
Use brand exclusions or keep brand in its own campaign so AI Max can't claim your cheapest conversions.
Negate the junk
Move the irrelevant bucket into a shared negative list. Review it weekly for the first month.
Exclude bad landing pages
Block careers, blog, policy and out-of-stock URLs from final URL expansion.
Promote the winners
New AI Max terms that convert under target become keywords of their own — then AI Max can go looking for the next ones.
Your AI Max routine weekly for the first month →
- Read the search terms report by source — split AI Max terms from keyword terms every week, and sort by spend.
- Track incremental CPA next to blended CPA — the gap between them is the size of the rerouting.
- Check the generated ad text — make sure automatic headlines don't promise discounts, delivery times or claims your page doesn't back up.
For the weekly habit of turning search terms into negatives and keywords, see search-term mining that pays for itself.
Quick gut-check
One question. If you get it, the whole post clicks. 30 seconds, tops
AI Max reports 200 conversions in its first month. Account spend rose ₹1,00,000 and total conversions rose by 50. Target CPA is ₹1,000. Is it working?
Frequently asked questions
Does AI Max replace my keywords?
No. Your keywords still run, but AI Max can match searches your keywords would have caught, and sometimes wins them first. That is why exact-match traffic can drop after you turn it on. Check whether those searches now cost more per click than they did through your keywords.
Is AI Max replacing Dynamic Search Ads?
Yes. Google announced that AI Max for Search will replace Dynamic Search Ads, with automatic upgrades planned from September 2026 and the deadline later moved to February 2027. Audit your setup before the upgrade happens to you.
How long should I test AI Max before deciding?
At least four weeks, plus enough time for conversion lag to settle — and longer if you get fewer than a few hundred conversions a month. A 50/50 campaign experiment gives the cleanest answer.
The summary
- AI Max labels every conversion it touches, including ones your keywords would have won anyway.
- Split AI Max traffic into rerouted, new and irrelevant searches using your search terms history.
- Judge it on incremental CPA — extra spend ÷ extra conversions — not on blended CPA or the summary card.
- Fence brand, negate junk, exclude bad URLs, and promote winning new terms to keywords.
- Test it properly before Google's upgrade deadline decides for you.
Takeaways for your next report
- AI Max's own conversion count includes demand you already owned — never judge it on that alone.
- Incremental CPA = extra spend ÷ extra conversions. Compare that to target, not blended CPA.
- A search term your keywords served before is rerouted, not new.
- Fence brand, add negative lists and exclude bad URLs before scaling AI Max.
- New terms that convert under target should become keywords of their own.
A/B Test Significance Playground
Enter visitors and conversions for control and variant to get a verdict, confidence, lift bounds and the sample size you actually needed.
Chinmay Raibagkar
About author →Founder of DataLens AI. He helps non-technical teams read their ad and database numbers with confidence — which number to trust, what to do next, and what to ignore.