Microsoft Advertising today published its monthly product newsletter, attaching a stated conversion uplift figure to the AI Max suite that reached every account globally three weeks ago and setting a January 12, 2027 cut-off for Max CPC bids submitted through its API.

In Short

Microsoft told advertisers that campaigns switching on all three parts of its AI Max system produced at least 8% more conversions in early testing, a figure the company measured itself and published without showing the working. The same newsletter confirmed that the maximum cost-per-click ceiling disappears from new campaigns on October 1, 2026, survives in campaigns created before that date, and stays available through the platform's API until January 12, 2027. Anyone buying search ads on Bing now has two dates to plan around rather than one.

What the newsletter says

The document reached advertisers through Microsoft Advertising's LinkedIn newsletter, which lists 9,650 subscribers and sits on a company page carrying 64,721 followers. Mascha Driessen, Vice President Continental Europe at Microsoft Advertising, identified the author in a comment, describing the edition as "well written by our very own Navah Hopkins". Hopkins holds the Microsoft Ads Liaison role and has been the platform's public voice on product changes since June 2025. At the time of capture the post carried seventeen reactions, six comments and one repost.

Seven topics run through the edition: the global availability of AI Max, changes to bidding controls, a holiday playbook for agentic commerce, data-driven attribution, the Model Context Protocol server, account verification and security, and pre-peak experimentation. Microsoft Advertising framed August as the month AI Max completed its rollout, and the newsletter functions partly as a consolidation of features shipped earlier in the year that, by the company's own account, advertisers had missed.

An 8% figure without a denominator

The headline performance claim is narrow and heavily conditioned. According to Microsoft Advertising, early testers of AI Max saw a conversion uplift of at least 8% when they adopted all parts of AI Max. Two qualifiers sit inside that single sentence. The uplift is a floor rather than an average, and it applies only to accounts that switched on search term matching, text customization and final URL expansion together rather than selectively.

What the newsletter does not supply is the surrounding apparatus. No sample size accompanies the figure. No measurement window is stated, no market or vertical breakdown appears, and there is no statement of whether the comparison was run through the platform's own experiments framework or assembled from before-and-after account data. Microsoft Advertising also recommends elsewhere in the same document that advertisers test AI Max through a 50/50 experiment split, which is the methodology the uplift claim itself does not describe.

A naming collision complicates independent verification. Google operates a product also called AI Max, and third-party measurement of that product has produced mixed readings, including the conversion contribution Etsy credited to Google's version during the 2025 holiday season. The two systems share a name, a broad function and nothing else verifiable. Vendor figures published for one are not evidence for the other.

Three settings, four caps

The AI Max panel presents three checkboxes beneath a master switch, a structure PPC Land documented when the suite reached all Microsoft Advertising accounts globally on August 19, 2026. Today's newsletter attaches numeric limits to the controls that sit alongside them.

Search term matching widens the pool of queries a campaign can enter, drawing on keywords, ads, landing pages, intent signals and contextual signals. Brand controls govern that expansion. Brand inclusions allow up to 20 brand lists per campaign, with up to 100 brands per list, and require search term matching to be active for campaigns to serve. Brand exclusions carry identical caps and operate with or without search term matching. The arithmetic gives a single campaign a theoretical ceiling of 2,000 brands on either side of the boundary.

Text customization generates and tests additional messaging variations from existing assets and website content, selecting combinations at auction time. Two controls constrain it. Term exclusions accept up to 25 exact terms blocked from AI-optimized ad copy, treated as exact matches and positioned by Microsoft Advertising as brand controls. Messaging guidelines accept up to 40 entries per campaign covering tone, format and phrasing.

Final URL expansion routes traffic to the page on an advertiser's site that best matches the query rather than to a fixed landing page.

The asymmetry between the two text controls is worth noting. Twenty-five blocked terms is a small list for a large brand with legal, regulatory or trademark constraints, while forty messaging guidelines is a comparatively generous allowance for directional instruction. The platform has weighted the softer control more heavily than the hard one.

What the search term report shows, and what it omits

Full search term reporting arrives through a search term landing page report template in the Reports interface. Twelve default columns populate it: search term, final URL, campaign, ad group, headline, delivered match type, final URL source, impressions, clicks, spend, conversions and conversion rate.

The reporting perimeter is set by a single condition. According to Microsoft Advertising, the report covers any query that results in a click. Queries that generated impressions without clicks fall outside it. For a system whose stated purpose is entering auctions the keyword list would not reach, the queries that produced no click are precisely the ones that would show where expansion went wrong. That data is not in the default template.

One prerequisite governs the entire suite. The newsletter carries it as an important note: turning on any AI Max feature requires conversion-based bidding. AI Max also remains opt-in for existing campaigns, while new campaigns present an explicit opt-out step during creation. Advertisers already testing AI-optimized assets for Search campaigns find that feature has moved into AI Max, and no other AI Max component activates without a separate opt-in.

Import behaviour carries its own mechanics. Search campaigns imported with AI Max features enabled arrive on Microsoft Advertising with those settings intact. An imported AI Max campaign that originated as an upgraded Dynamic Search Ads campaign converts back into DSA on Microsoft Advertising while the company builds out further functionality.

October 1 removes the ceiling, January 12 ends the reprieve

The bidding section resolves two questions PPC Land flagged as unanswered when the change surfaced in August. According to Microsoft Advertising, the company will be removing the ability to add a Max CPC to new campaigns using standalone Max Conversion, Max Conversion Value and Max Click bidding strategies on October 1, 2026.

That wording narrows the perimeter. When notification emails and a liaison post first confirmed the removal on August 20, 2026, the language covered new non-portfolio campaigns generally and said nothing about campaigns already running. Today's document names three specific strategies and lists four carve-outs: portfolio bidding strategies, existing campaigns created prior to October 1, 2026, Target Impression Share, and enhanced CPC.

The second resolution concerns tooling. Max CPCs implemented through the APIs will be maintained through the entire 2026 holiday season, which Microsoft Advertising dates to January 12, 2027. The August notice made no reference to programmatic campaign creation at all, leaving agencies running bulk workflows without a stated position.

Three dates now sit within four months of each other. New Microsoft Advertising API features become exclusive to the REST interface from October 1, 2026, a boundary set out when the company published its SOAP retirement schedule in April. API support for Max CPC ends on January 12, 2027. Full SOAP deprecation follows on January 31, 2027, nineteen days later.

Microsoft Advertising states its rationale in terms of measurement rather than revenue. The company is investing extensively in improving its bidding and measurement capabilities, according to the newsletter, and observes that advertisers using conversion targets meet goals more easily than those relying on legacy controls. Max CPCs override stated goals, the document argues, preventing campaigns from winning auctions that would still fall inside overall tCPA and tROAS goals, and producing spend pacing irregularities.

The company also restated a behaviour it has emphasised before: campaigns are permitted to overachieve on tCPA and tROAS regardless of budget-limited status. That posture runs opposite to the change Google began rolling out on August 17, 2026, which pushes over-performing targets back toward their stated figures in budget-limited campaigns across five formats.

The threshold that closes the loop

Conversion-based bidding depends on volume. The newsletter sets the working figure at 30 conversions in 30 days and describes three routes for accounts below it.

The first consolidates campaign structure or moves to portfolio bidding, using ad group level location targeting to merge markets into a single campaign where margins allow, and portfolio strategies where they do not. The second uses micro-conversions with journey-aligned conversion values, assigning weighted values to stages such as a form fill or a booked demo. Microsoft Advertising pairs that route with conversion value rules, arguing they steer budget across audience, location and device more effectively than bid adjustments, which the company says can cause bids to spike, or Max CPC, which it says can stunt serving in competitive auctions. The third holds off on conversion-based bidding entirely and runs enhanced CPC with bid adjustments.

That third path closes a loop worth tracing. AI Max requires conversion-based bidding. Conversion-based bidding needs roughly 30 conversions in 30 days to function well. An advertiser who cannot reach that threshold is directed to enhanced CPC, which is not conversion-based bidding, and therefore cannot switch on the suite carrying the 8% claim. The uplift figure and the volume threshold describe two different populations of advertiser.

Fractional conversions and a total above one

Data-driven attribution reached Microsoft Advertising earlier in 2026 and the newsletter revisits it as a reader question. Rather than assigning full conversion value to the last touchpoint before a sale, the model distributes credit across the touchpoints that preceded it.

The worked example in the document uses a single purchase. Under last-click attribution, audience ads record zero conversions, search ads record zero, and Performance Max records one. Under data-driven attribution the same purchase reads as 0.4 conversions for audience ads, 0.2 for search and 0.5 for Performance Max. Those three figures total 1.1.

Microsoft Advertising addresses the overage directly, stating that fractional conversions can sometimes add up to more than 100% of the full conversion depending on conversion windows and when the conversion actually landed. The practical consequence is that a channel-level sum in a data-driven attribution report is not a count of purchases, and reconciling it against a finance system requires matching conversion windows to goals. The company points to offline conversions and enhanced conversions as inputs that strengthen the underlying measurement.

Read-only agents before Black Friday

The Microsoft Advertising Model Context Protocol server remains in open pilot with read-only functions, the position it has held since it expanded to open pilot on June 17, 2026 alongside Web IQ and Clarity citation reporting. The newsletter frames it around seasonal workflows: auditing conversion tracking, Universal Event Tracking setup, Merchant Center readiness and campaign health before traffic peaks; surfacing budget constraints, inventory issues or feed problems; finding keyword and audience opportunities as shopping behaviour shifts; and converting competitive insights into optimisation recommendations.

The read-only constraint sets the boundary of that value. An assistant connected through the server can diagnose a pacing problem inside Microsoft 365 Copilot, ChatGPT or Claude, and cannot fix it. Execution returns to the interface. The protocol itself, an open standard published by Anthropic in November 2024, has become common infrastructure across the sell side and buy side, and the read-only posture places Microsoft Advertising among the more conservative implementations as agentic AI tooling spreads through campaign management.

Three pillars for AI shopping

The agentic commerce playbook, titled "How businesses win when AI does the shopping", organises around three headings.

Get discovered rests on catalogue completeness. AI can only recommend products it can find and understand, according to Microsoft Advertising, which directs advertisers toward accurate product feeds, full catalogue availability through Merchant Center and readiness for discovery through Universal Commerce Protocol. Be chosen covers influence at the point of decision through AI-native ad formats using AI Max or Performance Max, conversational assistants in the form of Brand Agents, and Copilot Checkout. Understand what's working covers measurement of AI visibility, citations, AI-referred traffic and on-site behaviour in Microsoft Clarity.

Two of those components have documented histories. Copilot Checkout and Brand Agents both arrived on January 8, 2026, three days before Google set out UCP at the National Retail Federation conference. Microsoft joined the UCP Tech Council in April 2026 alongside Amazon, Meta, Salesforce and Stripe. Adoption of the protocol has been slower than its endorsement list suggests: PPC Land found in May 2026 that only 26 sites had published the required profile, with the largest named backers absent.

Microsoft Advertising states the first-order conclusion plainly, describing product data as becoming more important than ever. That position is continuous with the answer engine and generative engine optimisation playbook the company published in January 2026, which set out how feed structure and schema markup determine whether a product surfaces in AI assistants at all. A webinar on agentic commerce is scheduled for October 8, 2026.

Verification friction, stated as deliberate

The security section addresses account sign-up and verification complaints without softening the position. Bad actors rarely look suspicious, according to Microsoft Advertising, which describes fraudulent accounts that appear legitimate, attempts to access existing advertiser accounts, and the use of account-linking relationships to gain unauthorised access.

Dual-ID account linking requirements are named as one of the resulting safeguards, adding validation before accounts can be connected and managed. The company acknowledges the cost, stating that the goal is not to make advertising harder but to keep a trusted ecosystem in which advertisers can invest confidently. On suspensions, the guidance runs toward appeal and documentation rather than account recreation, which the newsletter says can complicate review and lengthen resolution.

Account linking has become a recognised attack surface across search platforms. Google Ads began requiring passkeys for sensitive actions including account linking from July 15, 2026, and added a second-admin approval step that left single-administrator accounts unable to complete some operations. Microsoft's dual-ID requirement belongs to the same category of change and carries the same trade-off between security and operational speed.

An experiments window that does not fit every campaign

The closing section sets out a five-step testing sequence: one variable per test, a stable campaign with sufficient volume, a 50/50 traffic split, enough runtime for bidding systems to learn, and measurement against conversion rate, cost per acquisition, return on ad spend and changes in revenue or conversion value. Candidate tests named in the document include enabling AI Max on a high-volume Search campaign, running targets against no targets in Max Conversion and Maximize Conversion Value, broader keyword matching, new messaging against evergreen copy, expanded audience coverage, and an optimised product feed against the current one.

"The worst time to test a major optimization is during Black Friday week," the newsletter states, setting October as the point by which results ought to be known.

An eligibility gap sits underneath that advice. Microsoft's own documentation for Search optimization experiments, which PPC Land examined in August, restricts experiments to Search campaigns and excludes campaigns with Dynamic Search Ads enabled in campaign settings. Today's newsletter states that an imported AI Max campaign originating from an upgraded DSA campaign converts back into DSA on Microsoft Advertising. Advertisers who moved to Google's AI Max through the DSA upgrade path and then imported those campaigns would land in exactly the configuration that experiments cannot test. Neither document addresses the intersection.

Why this matters for media buyers

The two changes interact in a way neither section acknowledges. AI Max requires conversion-based bidding. Max Conversion and Max Conversion Value are the strategies losing their Max CPC field on October 1. The campaigns most likely to run the expansion suite are therefore the same campaigns that lose the hard ceiling on what a click can cost, during the quarter when auction pressure peaks.

Portfolio bidding is the stated route to keeping a ceiling, and it is not a neutral substitute. A portfolio governs several campaigns as one unit, allowing spend to move between them according to the platform's assessment rather than a buyer's allocation, which carries reporting and contractual consequences for agencies operating per-campaign commitments. Enhanced CPC keeps a base bid the system may exceed per auction. Target impression share keeps a ceiling but reorients the campaign around placement rather than conversions.

The API extension changes the practical calendar. Advertisers creating campaigns programmatically retain the field for a further fourteen weeks past October 1, which covers Black Friday, Cyber Monday and the post-Christmas sales period. Teams building campaigns in the interface do not. That split gives an operational advantage to accounts with API tooling, and it lands in a period when Microsoft has guided to mid-single-digit search advertising growth after reporting 10% growth excluding traffic acquisition costs for the quarter ended June 30, 2026.

For measurement teams, the attribution and AI Max sections pull in the same direction. Data-driven attribution redistributes credit across touchpoints, producing channel figures that no longer sum to whole conversions. AI Max expands the query surface while reporting only clicked queries. Both changes increase the distance between what a campaign does and what a report shows, at the point in the year when the reports carry the most weight.

Timeline

Summary

Who: Microsoft Advertising, through its monthly LinkedIn product newsletter written by Navah Hopkins, Microsoft Ads Liaison, and identified as such in a comment by Mascha Driessen, Vice President Continental Europe. The material affects advertisers, agencies and in-house teams running Search, Shopping and Performance Max campaigns on the platform, and specifically those creating campaigns through the API.

What: A seven-topic edition covering the global availability of AI Max with a stated conversion uplift of at least 8% for full adoption, numeric caps on brand and text controls, a twelve-column search term landing page report, the removal of Max CPC from three standalone bidding strategies, four carve-outs including existing campaigns and an API extension to January 12, 2027, data-driven attribution mechanics, a read-only Model Context Protocol pilot, a three-pillar agentic commerce playbook, dual-ID account linking, and a five-step experiments sequence.

When: Published September 9, 2026. The bidding restriction takes effect October 1, 2026. API support for Max CPC ends January 12, 2027, followed by full SOAP deprecation on January 31, 2027. A webinar on agentic commerce is scheduled for October 8, 2026.

Where: Across Microsoft Advertising globally, including AI Max availability in all accounts, and across the AI surfaces the playbook covers, among them Bing, Copilot, Merchant Center and Microsoft Clarity.

Why: Microsoft Advertising attributes the bidding change to a stated preference for conversion targets over hard bid ceilings, arguing that Max CPC overrides stated goals and creates pacing irregularities. The AI Max material addresses controls and reporting the company says advertisers identified as conditions for trusting automated campaign management. The security section positions verification friction as fraud prevention rather than administrative overhead. No rationale is published for the specific January 12, 2027 API date beyond its coverage of the 2026 holiday season.