Google Is Auto-Migrating Search Campaigns to AI Max — What Marketers Gain and Give Up
Google is automatically migrating legacy Search campaigns — those using campaign-level broad match or Automatically Created Assets — to AI Max throughout September 2026, and the change cannot be skipped. Advertisers stand to gain AI-driven reach and efficiency but give up granular control, making guardrails and reporting discipline essential.
A migration you can't opt out of
Google has begun automatically migrating legacy Search campaigns to AI Max, its AI-driven search offering. Campaigns still using campaign-level broad match or the old Automatically Created Assets are in the migration path, and the shift — rolling out through September 2026 — cannot be skipped.
AI Max expands where and how your search ads can appear, using Google's models to match queries, generate assets and find incremental demand beyond your exact keywords. For many advertisers, the system will simply switch on.
The trade: performance for control
The pitch is compelling. Google has pointed to double-digit gains in conversions for advertisers adopting AI Max, and automation genuinely can uncover queries and combinations a human would never build manually.
The cost is control. AI Max decides more about matching, creative and placement, which means less granular visibility and fewer manual levers. Marketing Minute's read: this is the same bargain the whole industry is being offered — hand the machine the keys in exchange for scale — and, increasingly, it is not optional.
What to watch once you're migrated
Search term reports, brand controls and negative keyword lists matter more after migration, not less. With the system casting a wider net, the risk is spend leaking into irrelevant or off-brand queries. Tight negatives and brand exclusions are how you keep AI reach from becoming AI waste.
Watch your data, too: AI Max changes what you can see in reporting, so agree in advance which metrics prove it is working — incremental conversions and profitability, not just a bigger conversion count.
What businesses should do now
Audit which campaigns are in the migration path and get ahead of it: refresh negative keyword lists, lock down brand controls, and set clear performance guardrails before the switch flips. Passive migration plus passive management is how budgets quietly bleed.
Then judge AI Max on incrementality, not vanity metrics. More conversions at worse economics is not a win — hold the automation to the same profit bar you'd hold a human buyer.
Quick FAQ
What is Google AI Max and who is being migrated?
AI Max is Google's AI-driven evolution of Search advertising. Google is automatically migrating legacy Search campaigns that use campaign-level broad match or Automatically Created Assets to AI Max through September 2026, and the change cannot be skipped.
What do advertisers gain and lose with AI Max?
They gain AI-driven reach, asset generation and, by Google's account, double-digit conversion gains for adopters. They lose granular control over matching, creative and placement, along with some reporting visibility.
How do I protect performance after migrating to AI Max?
Tighten negative keyword lists and brand controls to stop spend leaking into irrelevant queries, and judge results on incremental conversions and profitability rather than a raw conversion count.
AI Max is the industry bargain in miniature: hand Google the keys and get scale in return — except now there's no opt-out. Automation will find demand you never could, and waste you never sanctioned. The winners won't fight it; they'll fence it with tight negatives, brand controls and a hard profit bar. — Daniel Nikolla, Founder of Merx Marketing
When automation becomes mandatory, control moves from the settings to the guardrails — win by managing negatives, brand safety and incrementality, not by clinging to manual levers.
When the machine casts a wider net, do you have the negatives and brand controls to keep reach from becoming waste?
If you would like to know more about this topic, please contact us on danieln@merxmarketing.co.uk
Sources: Search Engine Land, Search Engine Roundtable, Google, Improvado.
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Written by Daniel Nikolla, Founder of Merx Marketing Ltd and Marketing Minute
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