Google Just Auto-Migrated Your Search Campaigns to AI Max. Microsoft Made It Opt-In. That Contrast Matters.

Two ad platforms made structurally similar moves in the same month and chose opposite defaults. Beginning September 1, 2026, Google started automatically upgrading Search campaigns that use campaign-level Broad Match or standalone Automatically Created Assets to AI Max, rolling the migration out progressively through the end of September rather than all at once. Campaigns move in place with equivalent settings, and existing brand inclusions and exclusions carry over automatically - but the underlying matching and asset-generation logic changes whether an advertiser asked for that or not. Microsoft, rolling out its own AI Max for Search globally the same month, took the other path: AI Max is on by default for new campaigns only, remains fully opt-in for existing ones, and can be switched off at any point.

Same underlying trend - AI-driven query matching and creative generation replacing manually enumerated keywords and assets - handled with opposite philosophies about consent. That contrast is the actual story, more than either rollout individually.

What's actually shifting

The mechanism in both cases is the same directional move that's been reshaping organic search for the past year: control over what triggers your presence in front of a buyer is shifting from the advertiser explicitly specifying it to the platform's model inferring it in real time. Broad Match and Automatically Created Assets were already steps in that direction; AI Max extends it further, letting the platform decide more of the query-to-ad and asset-to-query matching itself. For advertisers who've built precise, hand-tuned account structures, that's a meaningful loss of granular control - even when the stated goal, on both platforms' part, is better performance.

We've made a version of this argument before about ChatGPT's own move into sponsored placements: as more of the interface between a brand and a buyer gets mediated by a model rather than a manually configured rule, the signals that decide what a model surfaces - structured facts, consistent framing, trustworthy third-party corroboration - start to matter more than the manual levers marketers are used to pulling. AI Max is that same shift showing up on the paid side, inside Google's and Microsoft's own ad platforms rather than inside ChatGPT's answer surface.

Why the auto-migration vs. opt-in split is worth noticing

Google forcing the change for a defined subset of campaign types - specifically ones already using Broad Match or standalone ACA - removes the choice for advertisers running those setups; if you didn't act before September 1, you're on AI Max for those campaigns now, migrated with your existing settings but under the new logic. Microsoft's decision to hold AI Max at opt-in, even while making it the default for anything newly created, is a deliberate acknowledgment that some advertisers want deterministic control and shouldn't lose it by inertia.

For any team running accounts across both platforms, that means September 2026 requires two different postures at once: an audit of what already got migrated on Google, and a deliberate decision - not a default - on Microsoft. Reporting that assumes both platforms behave the same way this month will be wrong on at least one side.

What to actually do

1. Audit which active campaigns use campaign-level Broad Match or standalone Automatically Created Assets. Those are the ones Google is moving automatically through September - know which of your campaigns already changed underneath you.
2. On Microsoft, decide on purpose. AI Max defaults to on for new campaigns but stays reversible - don't let it become your account's default by nobody unchecking a box.
3. Track organic AI citation separately from either ad console. As matching logic on both platforms shifts toward model inference, the clearest signal of whether your brand is actually legible to a model - the same legibility that increasingly drives paid matching too - is your citation rate in AI answers themselves, not campaign performance metrics inside either ads platform. GetBotRank's Visibility Tracker measures that directly, independent of what either Google Ads or Microsoft Advertising reports back to you.

Paid and organic have always been measured separately. As both increasingly run on the same underlying capability - a model deciding what's relevant to show - that separation in measurement is exactly what will let a change like this one pass unnoticed until it shows up in results nobody can quite explain.