Google Ads Liaison: channel caps in the API at launch, PMax Search partners can go to 0%

Google's Ads Product Liaison, Ginny Marvin, said in the Ads Decoded newsletter dated 16 October 2026 that the new channel prioritization and budget allocation controls are supported in the Google Ads API at launch, that Performance Max advertisers can set the budget allocation for Search partners to 0%, and that Smart Bidding Exploration is now fully launched for Performance Max campaigns with a product feed and for Shopping campaigns. According to PPC Land's 17 October report on the newsletter, several of those answers go further than Google's own help page, which still listed API support as "coming soon" when Relevant Audience checked it on 18 October 2026.

This is a follow-up. Relevant Audience covered the launch of the two controls on 15 October 2026 and the related 15 October Ads Decoded podcast with Google product manager Tal Akabas on 17 October 2026. This article covers only what the 16 October newsletter adds and where it conflicts with earlier Google material.

Where these answers come from

The newsletter is an edition of Ads Decoded, published on the Google Ads LinkedIn page, signed by Marvin and titled "The big-picture guide to directing your ad spend". PPC Land dates it 16 October 2026 and reports that it was linked the same day from the AdsLiaison account on X; LinkedIn shows the date as 17 October when viewed from Thailand. Relevant Audience checked the Marvin quotes below against the LinkedIn newsletter itself. Statements about the X post and about earlier Google material are as reported by PPC Land. Where the newsletter and Google's help page differ, both versions are given.

PPC Land says the newsletter has four parts: a question-and-answer section on channel prioritization and budget allocation, three bidding and budget features "rolling out in time for the holiday push", a section on customer lifecycle goals, and a four-step planning framework. Marvin answered seven questions. PPC Land counts four answers that go further than, or diverge from, the help page.

What is new compared with the 14 October launch

Google announced channel prioritization and budget allocation on the Google Ads & Commerce Blog on 14 October 2026 in a post by Tal Akabas, Director of Product Management. That post describes campaigns that "fully fund" High priority channels before sending the remaining budget to Low priority ones, and a maximum percentage of the daily budget for Low priority channels, which Google's tools aim to respect "on a best-effort basis". It says the features roll out to Search, Shopping, Performance Max and Demand Gen "over the next months".

The newsletter repeats that core mechanism. The first three items below cover the four answers PPC Land says go further than, or diverge from, the help page. The last two are clarifications; account-level defaults were already covered in Relevant Audience's 15 October article.

• API at launch. Marvin wrote: "They are supported via the Google Ads API at launch, with Google Ads Editor support coming soon." The help page says "Support for the Google Ads API and Google Ads Editor is coming soon" and names only Google Ads and Search Ads 360 as places to manage the settings; that wording was unchanged when checked on 18 October 2026.
• Search partners at 0% in Performance Max. "On PMax, you'll be able to set a budget allocation for SPN to 0% if desired or test increasing the max percentage daily budget allocation," Marvin wrote. SPN is Google's abbreviation for the Search Partner Network.
• Experiments and shared budgets. Marvin called the settings "fully testable using campaign Drafts & Experiments" and "fully compatible and supported when using shared budgets". The help page sets limits on both.
• Existing opt-outs stay. "Existing opt-in/opt-out settings for the Display Network and Search partners are unchanged," and "individual placement controls also remain."
• Account-level defaults. Settings can be applied at account level as defaults "per campaign type", which campaigns "inherit", and can be overridden at campaign level.

Search partners at 0% in Performance Max: what it is and what it is not

PPC Land notes that a setting allowing some Performance Max advertisers to switch off Search partners and the Display Network was spotted in an alpha test on 30 April 2026, and that in late July Google confirmed it was a pilot limited to selected advertisers.

The 0% allocation is a different instrument. The help page already said on 14 October that a 0% allocation on a Low priority channel means "Google won't spend on that channel". What the newsletter adds is the explicit statement that this applies to Search partners in Performance Max. To use it, the channel must first be marked Low priority, because the cap exists only on the Low priority tier.

PPC Land points out one caveat that the newsletter does not repeat. The help page describes every allocation as a target Google "will aim to" respect and adds that "this isn't a guarantee". Marvin's answer does not say whether a 0% setting is exempt from that best-effort wording. As PPC Land puts it, only placement reports will show whether Google's systems hold a 0% line in practice.

API at launch versus "coming soon": why it matters for agencies

The API answer is the clearest conflict between the two documents. The help page also says the controls cannot be set from a manager account. An agency that wants to apply the same cap across many client accounts therefore has two routes: one account at a time in the interface, or the API. If the newsletter is right, bulk configuration through the API is possible now. If the help page is right, it is not yet.

PPC Land notes that the newsletter does not name an API version or the resources that expose the settings, and does not address manager accounts. Editor support remains "coming soon" in both documents.

Where the newsletter and the help page differ

PPC Land compared the two documents line by line. The table below gives its comparison of Google's help page as of 14 October 2026 against Marvin's newsletter of 16 October 2026.

Two of these need context. On shared budgets, PPC Land notes that Google's separate shared budgets page lists Performance Max as incompatible with shared budgets, so "fully compatible" can only apply to campaign types that can use shared budgets at all. On rollout pace, the same author wrote "coming months" on LinkedIn and "coming weeks" on X on the same day; the 14 October blog post said "over the next months".

PPC Land also flags two omissions. The newsletter does not mention the help page's statement that the Display Network will stop serving on Search campaigns that use Target Impression Share once the February 2027 change applies. And the Target CPA and Target ROAS answer is blank: the heading appears with no text under it, both in PPC Land's capture and on the LinkedIn page as checked on 18 October 2026. The help page fills that gap: for Target CPA and Target ROAS campaigns not limited by budget, "priority levels generally don't change how spend is distributed", and only the percentage allocation has an effect. Marvin did write that "these are budgeting controls and not bidding controls".

The February 2027 Display change is restated

"For Search campaigns opted into GDN, the current spend allocation setup will go away, starting Feb '27," Marvin wrote. To keep the current configuration, advertisers can set the Display Network to Low priority with a 50% budget allocation. That matches Google's 14 October blog post. No new reporting was added for any of this: Marvin pointed to existing network segmentation and placement reporting in Search and Shopping, the channel performance report and placement reporting in Performance Max, and network segmentation in Demand Gen.

Three holiday features in the same newsletter

The second part of the newsletter lists three features "rolling out in time for the holiday push". Two carry status changes or figures that Google had not published before.

Smart Bidding Exploration is "fully launched" for retail

Marvin wrote that Smart Bidding Exploration, "which gives the system a small ROAS tolerance to bid opportunistically and find incremental auctions, is now fully launched for PMax retail (with a product feed) and Shopping campaigns", and that it "requires uncapped budgets to function properly". PPC Land traces the status history: Google said on 7 May 2026 that it would extend the feature to feed-based Performance Max and Shopping, and by 22 June both were in a restricted beta. In the 15 October podcast Marvin had described it as "rolling out" for retail Performance Max and "coming to" Shopping. The newsletter, one day later, says both are fully launched. The uncapped budget requirement means a campaign held back by its daily budget gets less from Exploration.

Promotion mode gets a 5% to 90% ROAS tolerance range

Promotion mode is "rolling out in beta on Search and PMax", Marvin wrote. It "allows you to schedule a promotional period and set a ROAS tolerance between 5-90%, leveraging Smart Bidding Exploration". An optional budget boost can apply during the promotion, and "once the promotion ends, it automatically reverts to your original settings." PPC Land says the 5% to 90% range had not been published before: when promotion mode entered beta on 15 June 2026, Google's material described temporary ROAS tolerance changes without a range, and a clarification from Marvin a week later gave promotion windows of 3 to 14 days. The newsletter does not say how the percentage is applied, and does not repeat the 3 to 14 day window. It also still calls promotion mode a beta, while Akabas said on the 15 October podcast that it was "rolling out just now".

Campaign total budgets: 3 to 90 days

Campaign total budgets are "designed for new campaigns to advertise short-lived promotions", with a fixed total spend over a duration "between 3 and 90 days". Marvin suggests pairing them with promotion mode for "short-burst sales". PPC Land adds a limit from the help page that the newsletter does not mention: channel prioritization works with campaign total budgets only in Demand Gen. A Search or Performance Max holiday campaign on a total budget cannot use the new channel tiers, so on current documentation no campaign type supports all three features together.

What the newsletter did not say

• It did not name an API version or API resources for the new settings.
• It did not say whether a 0% allocation is exempt from the best-effort wording on the help page.
• It did not address manager accounts, Demand Gen budget allocation or the Target Impression Share change on Search.
• It did not explain how the promotion mode ROAS tolerance percentage is calculated, and Google has published no results for the feature.
• It gave no market-by-market rollout schedule. The controls are described as rolling out globally.

What to check in your own account

The steps below are practical analysis based on the sourced statements above, not Google instructions.

1. Look for the setting before you plan around it. The help page puts the start of progressive availability at 15 October 2026, and Google's own wording on pace varies between weeks and months.
2. If you want Search partners out of Performance Max, mark Search partners Low priority, set the allocation to 0%, then check the channel performance report and Search partner placement reporting over the following days to confirm spend has stopped.
3. If you manage many accounts, test the API route on one account before planning a bulk change. The two Google documents disagree on whether it is available.
4. Do not rely on experiments for a clean read if your test involves multi-campaign shared budgets, since the help page says those are not supported and channels are treated as one tier in experiments.
5. Check Search campaigns with Display Expansion ahead of February 2027 and decide whether Low priority at 50% is the setting you actually want.
6. For holiday retail campaigns, check whether budgets are capping Performance Max or Shopping campaigns where you expect Smart Bidding Exploration to work, given Marvin's statement that it needs uncapped budgets.

If you want help applying these controls across Search, Shopping and Performance Max, Relevant Audience's Google Ads management team can review channel spend and set up the tests. Retailers planning feed-based campaigns for the sales season can also look at Relevant Audience's ecommerce marketing services.

What this means for Thai marketers

Google describes the rollout as global and neither the blog post nor the newsletter gives a Thailand-specific date, so Thai accounts should expect the settings to appear gradually. For Thai ecommerce advertisers running Performance Max and Shopping through the year-end sales calendar, including double-date sales such as 11.11 and 12.12, three items matter most: the option to send no budget to Search partners in Performance Max, Smart Bidding Exploration now described as fully launched for feed-based campaigns, and promotion mode with its scheduled period and automatic revert. The budget arithmetic is the same in any currency: Google's help page applies the percentage to the average daily budget, so as an illustration a 5% allocation on a 10,000 baht average daily budget means Google aims to keep that channel at or below about 500 baht a day, on a best-effort basis.

FAQ

Can Performance Max advertisers now stop spending on Search partners?

Yes, according to Ginny Marvin's 16 October 2026 Ads Decoded newsletter, Performance Max advertisers can set the Search Partner Network budget allocation to 0% after marking it Low priority. Google's help page calls every allocation best-effort and "not a guarantee", and the newsletter does not say whether 0% is exempt, so check placement and channel reports after applying it.

Are channel prioritization settings available in the Google Ads API?

Marvin wrote that they are "supported via the Google Ads API at launch", but Google's help page still listed API support as coming soon when checked on 18 October 2026. The two have not been reconciled publicly, and the newsletter names no API version, so test on one account first.

Is Smart Bidding Exploration available for Shopping campaigns?

Yes, Marvin's newsletter says Smart Bidding Exploration is "now fully launched" for Performance Max retail campaigns with a product feed and for Shopping campaigns. She added that it requires uncapped budgets to work properly.

What ROAS tolerance can promotion mode use?

The newsletter says promotion mode lets advertisers set a ROAS tolerance between 5% and 90% for a scheduled promotional period, a range PPC Land says Google had not published before. It does not explain how the percentage is calculated, and promotion mode is still described as a beta on Search and Performance Max.

Do I have to change anything now?

No change is required now for the new controls, which are optional, but Search campaigns with Display Expansion lose their current spend allocation setup starting in February 2027. Google says Low priority with a 50% allocation on the Display Network keeps the current configuration.

Google has now described the same two settings in a blog post, a help page, a podcast and a newsletter within three days, and the four do not fully agree. Our view: until Google updates the help page, plan around the stricter version and verify spend in the reports.