Google Ads AI Max includes a text customization feature that generates responsive search ad assets automatically for each ad group. A team of PPC specialists ran controlled experiments with three companies, an ecommerce retailer, a B2B lead generation business, and a B2C lead generation business, to measure how the auto-created assets performed against human-written copy. The results split sharply by campaign type and by how much manual optimization the campaigns already received.
How the test was set up
The team enabled AI Max and turned on text customization in each account. To keep the generated assets on message, they built messaging restrictions using a short prompt workflow in Gemini: first generate baseline assets, then deliberately ask the system to produce overly promotional or off-brand variations, then write restrictions that block those patterns, then iterate with new prompts until every output aligns with the company’s brand guidelines. The whole setup typically took an hour or two.
From each account they selected four campaigns for the test: two that the in-house team actively optimized, and two long-tail campaigns that received less attention. Filters required no brand keywords, at least $20,000 in monthly spend, and at least 100 ad groups. They excluded campaigns that relied heavily on pinning, because pinning overrides the auto-created assets, and they disabled URL expansion so the test isolated copy alone.
One operational note showed up in every account: the default asset review filter in Google Ads does not show AI-generated assets. Reviewers had to change the filter to include “Auto-created” before they could see what the system was producing. Across the ecommerce and B2C accounts, roughly 19% of the auto-created assets were removed during the test period because they strayed from approved offers or brand voice.
Ecommerce results: top campaigns lost, long-tail won
The ecommerce account sells more than 100,000 SKUs, and many shoppers will revisit the site and search again if the landing page does not match what they want. On the surface, AI Max text customization looked like a clear win. After deeper analysis, the team found that AI Max was poaching impressions, clicks, and conversions from the account’s other campaigns, and total revenue for the account declined during the test. The company added high-performing search terms as keywords to push the system toward the right ad groups, layered in more negative keywords and audience exclusions, and reran the tests.
Revised conclusion for ecommerce: AI-driven text customization did not match human-managed assets on highly optimized campaigns. It did help on the long-tail campaign, where each ad group had received less individual attention.
B2B lead gen results: CTR rose, conversion rate collapsed
The B2B account had previously pinned its RSA assets heavily to make sure ad copy prequalified searchers as business buyers rather than consumers. For the test, the team removed those pins and let AI Max generate the assets. The nuance of prequalifying a B2B audience is one that text customization clearly doesn’t understand. Click-through rates climbed sharply, but conversion rates fell because the new ads were pulling in B2C searchers.
The messaging restrictions included language asking the system to prequalify for a B2B audience. Some individual assets met the criterion, but the ads users actually saw did not consistently appeal to business buyers. The B2B account stopped the test after three weeks, restored its pins, and removed the auto-created assets. Within a week, the account’s performance returned to its pretest baseline.
B2C lead gen results: a clear win on neglected campaigns
For B2C lead gen, the test company localizes ads through geo-targeted copy and inserts. Its optimized campaigns had tailored ad copy in nearly every ad group, while its long-tail campaign reused a few generic headline assets across ad groups. That gap is a common pattern in large accounts, and it set up a clean comparison.
AI Max auto-created assets didn’t outperform the hand-tuned top campaigns, but they performed well on the long-tail campaign, where the bar was human-written copy that had been reused across many ad groups with little customization. For advertisers who do not have time to write unique assets for every long-tail ad group, the auto-created assets improved the account’s overall baseline.
Where AI Max automated assets work best
Across all three accounts, the pattern was consistent. Human-written assets still beat AI-generated assets when the team had already invested significant time in optimization. Text customization also struggles with copy that has to do specific jobs, such as prequalifying B2B buyers, promoting specific offers, or running short-term promotions, because the system generates broad, generic variations rather than audience-specific ones.
Auto-created assets earn their keep in the places a PPC team does not have time to optimize: long-tail campaigns, ad groups with generic copy, and accounts where every ad group cannot get human attention. The caveat is that the feature still needs active oversight. Reviewers have to flip the asset filter to see AI-generated assets, remove roughly one in five before they accrue impressions, and watch for cannibalization across campaigns. AI in Google Ads is a long way from a turn-on-and-forget setting, but as a way to upgrade neglected campaigns while the team focuses on the high-priority ones, the text customization feature inside AI Max delivered measurable gains in two of the three test accounts.
FAQ
What is Google Ads AI Max text customization?
Text customization is a feature inside Google Ads AI Max that automatically generates responsive search ad assets for each ad group based on the keywords in that group. It can be paired with messaging restrictions to guide the system’s output.
How well did AI Max text customization perform in the ecommerce test?
It underperformed human-written assets on highly optimized campaigns and initially cannibalized traffic from other campaigns, which reduced total revenue. After adding new keywords, negatives, and audience exclusions, it improved performance on the long-tail campaign.
Why did AI Max text customization fail for the B2B account?
The auto-created assets did not consistently prequalify searchers as business buyers, so click-through rates rose while conversion rates fell. The account stopped the test after three weeks, restored its pinned assets, and returned to its pretest performance within a week.
This article summarizes reporting from searchengineland.com. See our editorial disclaimer for how our articles are produced.
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