Google has begun alpha testing a Performance Max setting that lets advertisers push the algorithm toward or away from specific channels, according to a Search Engine Land report. The change touches the core premise of Performance Max: that the advertiser hands over channel selection and lets the system decide. Search Engine Land, citing Search Marketing Advisor Heidi Sturrock’s LinkedIn post, reported the feature covers Search, YouTube, Display, Discover, Gmail and Maps.
The mechanism is an adjustment, not a budget split. A positive setting on a channel relaxes the cost-per-acquisition the system will accept there, telling Performance Max that conversions from that source carry more value to the advertiser. A negative setting tightens the accepted CPA, which pushes the algorithm to pull back on that channel. Google’s own documentation has stated that advertisers cannot directly control how Performance Max allocates budget by channel, which is what makes this test notable.
This is a control over economics, not inventory. An advertiser cannot yet tell Performance Max to spend a fixed percentage on YouTube versus Search. Instead, the advertiser is reshaping the cost threshold the algorithm applies when it decides whether a conversion opportunity on a given channel is worth pursuing. That distinction matters: a CPA nudge can be reversed or tuned incrementally, while a hard budget split would remove much of the automation Performance Max was built to provide.
The test arrives after Google shipped channel-level Performance Max reporting, which gave advertisers visibility into where their campaigns were actually serving and spending. Visibility alone does not let an advertiser act on what the report shows. A direct adjustment control would close that gap, turning a diagnostic into a lever.
Attribution is the part of this story Google has not resolved. Channel-level performance data is not the same as channel-level value. A shopper might see a YouTube ad first and convert later through a Search click, which means Search receives the credit for a conversion YouTube helped generate. An advertiser who tightens YouTube because its directly attributed CPA looks weak risks starving a channel that was doing real work higher in the funnel, and the resulting drop could show up as fewer conversions elsewhere in the campaign rather than in YouTube’s own numbers.
Search Engine Land frames this as one of the more consequential controls Google has introduced for Performance Max, since advertisers have pushed for more say over channel mix since the campaign type launched. The tradeoff is that the control adds a new decision for marketers to get right. Before pulling back on a channel, a team needs a view of that channel’s role across the customer journey, not just its last-touch CPA, or the adjustment could suppress performance instead of fixing it.
Teams running Performance Max should treat this alpha as a preview, not a rollout, and start building the cross-channel attribution view they will need before touching any channel adjustment once the setting becomes broadly available. Getting that groundwork in place now determines whether the new lever corrects a real allocation problem or introduces a new one.
Search Engine Land reported this alpha test on August 25, 2026, in a story by Anu Adegbola.
