Measurement

Google's spam update ran 13 days. Rule it out before you blame AI Overviews for your traffic drop.

By Arnav Mukherjee, founder of TofuBofu · October 10, 2026

On 5 October an SEO who works with B2B clients posted a question on r/SEO. Those clients used to get leads from informational articles. "Now I can see AI Overviews answering most of those queries directly, so people just don't click anymore. The problem is that clients don't get it. They think SEO is broken, or that adding an FAQ section will fix everything."

The thread had 49 comments when I read it on 10 October. Most replies went to how to explain it. A few asked whether AI Overviews was the cause at all. None mentioned the spam update Google was running that week, which it finished on 8 October. Two things can take your clicks in the same fortnight, and they need opposite responses. Search Console can narrow down which one you've got.

Did your drop start inside the 13-day spam update?

Start with the calendar, because it costs nothing. Google's dashboard gives these facts about the September 2026 spam update:

• Released: 24 September 2026.
• Completed: "The rollout was complete as of October 8, 2026."
• Reach: it "applies globally and to all languages."
• Length: 13 days and 15 hours by the dashboard's timestamps. The March, June and August spam updates each finished inside three days, so this was the longest of the four the dashboard lists for 2026.

Open your Search Console Performance report and find the day your clicks turned. Then read it against those dates:

• A step down between 24 September and 8 October makes the update a candidate. It doesn't make it the cause.
• A slow slide over months that began well before 24 September fits the answer box better than a rollout with a start date.
• Both at once is possible. A site can lose clicks to AI Overviews all summer and then lose rank in September.

The calendar narrows it. The next two checks decide it.

What does an AI Overviews loss look like in Search Console?

Google's documentation says three things that matter here:

• Where it's counted. Sites appearing in AI features such as AI Overviews and AI Mode "are included in the overall search traffic in Search Console", in the Performance report, within the Web search type.
• Clicks. "Clicking a link to an external page in the AI Overview counts as a click."
• Position. "An AI Overview occupies a single position in search results, and all links in the AI Overview are assigned that same position."

The same page says the position Search Console records is "the topmost position occupied by a link to your property or page in search results". Put the two rules together and you get our read, which is ours, since Google doesn't spell it out. A page linked inside an overview records the overview's position. What changes is how many people click anything at all. So for a page Google links in the overview, the two causes leave different marks:

• Answer-box loss: impressions steady or up, average position steady, clicks and click-through rate down.
• Ranking loss: average position down by several places, with impressions and clicks falling too.

Three cautions follow from the same rules:

• A steady position can hide a fall. If your page is linked in the overview and also ranks below it, the report shows the overview's slot. Your ordinary listing can drop underneath and the number won't move.
• A one-place slip can be the overview itself. An overview takes a position. A page it doesn't link sits one place lower when it appears, with no ranking change.
• AI Mode is counted differently. Google says position in AI Mode "follows the same methodology as a Google Search results page." The single-position rule is for AI Overviews.

One commenter in the thread accepted that pattern and added a warning: "If your rank positions held in 1-3 and your clicks fell- fair enough, thats an AIO drop. But how many people look at page average drops v position per query drops?" Take the warning. A page's average blends every query it ranks for, so a page-level read is a first cut. Check the top queries for each page before you call it.

How do you build the control group?

The best line in the thread came from a commenter called marintkael: "a control group did it for me. split the informational queries into ones with an AI Overview and ones without. if only the overview ones lost clicks, the client believes it. if both dropped, it's a ranking problem and Google was never the story."

Search Console won't hand you that split by query. It'll hand you a weaker one by page: the pages Google links in AI answers, against the pages it doesn't. The generative AI performance report covers AI Overviews and AI Mode, and Google defines its one metric plainly: "Impressions are how many times links to your site were shown to a user in a generative AI feature on Google Search." Its Pages tab is your list. Four steps:

1. List the pages Google links in AI answers. Open the generative AI performance report, choose the Pages tab, and note every page with impressions. Call this group A.
2. Pick two equal periods. In the ordinary Performance report, use the date filter to compare a period that ends before 24 September with a later one of the same length, starting on the same weekday.
3. Pull clicks, impressions and position by page. Use the Pages tab with all three metrics switched on for both periods.
4. Split and compare. Group A is the pages from step one. Group B is every other page that earned impressions. Total each group for both periods.

Know what group B is before you read it. Those are pages Google didn't link in an AI answer. An overview can still answer their queries and link a rival, so group B isn't free of AI Overviews. It's the group where Google's report can't show you the effect.

A small site may have no group A at all. Google's help page says the report usually doesn't appear when a site "hasn't received enough impressions in generative AI features." In that case skip to the query check in outcome 4.

A note on timing. I'm writing this two days after the rollout ended. There's barely one complete day of post-update data, and Google says the newest data can be preliminary. For a comparison free of the update, wait until 14 days have passed since 8 October. If you can't wait, compare the 14 days from 24 September against the 14 before, and say in the report that you measured an update in motion.

What do the four outcomes mean, and what do you do about each?

These are our readings of the patterns. Google publishes the counting rules and leaves the diagnosis to you.

1. AI-linked pages lost clicks, the others held

• What you see: group A's clicks are down, its impressions and position are steady. Group B looks normal.
• What it points to: the answer is being read on the results page. This is the cleanest result the method gives.
• What to do: stop measuring those pages by visits. Move to the plan in the next section.

2. Both groups lost clicks, and position fell

• What you see: average position is down by several places in group B. Group A's position may not move, for the reason in the first caution above.
• What it points to: a ranking change. If it began between 24 September and 8 October, the spam update is a candidate.
• What to do: read Google's spam policies against the pages that fell. Content written for the answer box won't fix a ranking problem.

3. Both groups lost clicks, position held, impressions fell

• What you see: impressions are down everywhere while rank is steady. If impressions held too, treat it as outcome 4 across the whole site.
• What it points to: fewer searches. That can be the season, or buyers asking somewhere else.
• What to do: compare against the same weeks last year, then check whether the engines your buyers use name you.

4. The other pages lost clicks, AI-linked pages held

• What you see: the damage sits in group B.
• What it points to: nothing yet. An overview that links a rival can be taking these clicks. So can a rival's new page, a technical fault, or a ranking change on a few URLs.
• What to do: sort group B by clicks lost. For the top pages, open their top queries in a signed-out browser and see whether an overview appears and who it links.

And if neither group lost clicks, the drop isn't in Google Search. Look at your other channels before you touch a page.

Where does this method fall short?

• Group B isn't a clean control. The commenter split queries by whether an overview appears. Google's report lets you split pages by whether it links them. A page losing clicks to an overview that links someone else lands in group B.
• It's page-level. The generative AI report had four dimensions when we read it: Pages, Countries, Dates and Devices. There's no query dimension, so a page can sit in group A for one query and lose rank on another.
• It has no clicks. That report counts impressions. Clicks from an overview are folded into the ordinary Performance report, and the pages we read give no way to separate them.
• It mixes two features. AI Overviews and AI Mode are reported together, and their position rules differ.
• It's capped. Google says the usual 1,000 row limit applies to the table.
• A date match isn't a cause. We haven't measured what the September update did to any site, and a drop inside its window can have another source.
• It's Google. ChatGPT, Claude, Perplexity and Gemini don't appear in Search Console at all.

What do you change once it's the answer box?

A diagnosis won't keep a client or calm a board. One commenter who lost a client said so from experience: "I did lose a client over this. They moved to another agency, but the underlying problem didn't disappear." Their lesson: "explaining what is happening isn't enough, clients also need to see a credible plan for what comes next." Another commenter laid out a three-part plan in the same thread. It's the best one I read, and I'd run it as written:

• Change the headline number. Lead the report with leads and how they found you. In that commenter's words: "If leads held while sessions fell, the client has lost nothing, and the report should say so."
• Show the reading that happens without a visit. Put group A's AI impressions beside its clicks. The commenter's line for the client: "the answer is being read without the visit".
• Change what you write. Their advice was to stop writing "the how-to posts the Overview answers in two lines" and write "pricing, comparisons, your own data, the pages an AI can only point to". We've argued the same from our own scans.

Then widen the lens past Google. G2's 2026 report found that 51% of B2B software buyers begin their software research with an AI chatbot more often than with Google. Those conversations leave no trace in Search Console. To see them, put your buyers' questions to each engine, record who gets named, and repeat the same questions every month.

SEO is still the floor. An engine that retrieves has to find your page before it can cite it, so a ranking loss needs fixing whatever else is true. Being named in the answer is a separate layer above that floor, and you can win it while your Google clicks stay flat. How to measure that layer with no traffic to count.

Frequently asked questions

Sources and further reading

• Google Search Status Dashboard: September 2026 spam update, read at source 10 October 2026: release on 24 September, completion on 8 October and global reach. The March, June and August spam update dates are on the dashboard's history
• Google Search Central: AI features and your website, read at source 10 October 2026: AI Overviews and AI Mode are counted in the Performance report within the Web search type
• Search Console Help: What are impressions, position, and clicks?, read at source 10 October 2026: the click and single-position rules for AI Overviews, the AI Mode position rule, and how average position is recorded
• Search Console Help: Generative AI performance report (Search), read at source 10 October 2026: the impressions definition, the four dimensions, the 1,000 row limit and when the report doesn't appear
• G2: The Answer Economy, 2026 AI Search Insight Report, n=1,076 B2B software buyers, surveyed March 2026: 51% begin software research with an AI chatbot more often than with Google
• r/SEO: How do you explain to clients that traffic dropped because of AI Overviews?, 5 October 2026: the question this post opens with, the control-group idea, the reporting plan, and the four commenters quoted