Across the e-commerce brands we track, organic search traffic in September and October came in 20% under their 2026 monthly average. Google rolled out a handful of AI Overviews changes at the end of August, and September is when the numbers fell off.

We were curious how brands were adjusting their ad spend as all of this played out. Google Ads spend was flat in September and up 8% in October. TikTok was the only channel that moved much, though it's still a small line item for most brands.

Everything below comes from ThoughtMetric attribution data for 200 e-commerce brands, January through October 2026.

What happened to organic search traffic

For most of the year organic traffic barely moved, staying within 7% of average from January through August. Then September came in 16% lower than August. October was no better.

January: +2%
February: −12%
March: +6%
April: +4%
May: +7%
June: −1%
July: −1%
August: −5%
September: −20%
October: −20%

February looks bad too, but that's mostly because it only has 28 days. Per day, it was about 3% under average. September and October were the worst two months of the year.

Most brands felt it. About two-thirds ended September and October below their own average, and roughly 40% were down 20% or more.

Google hasn't confirmed a core update since May.

What Google changed

Google made four changes to AI search in late August and September.

August 19, 2026. Generative UI, including custom calculators and interactive tools, expanded from AI Mode into AI Overviews.
August 27–28, 2026. Google confirmed AI Overviews now expand to full screen on their own for some queries, pushing organic links below the fold.
September 2, 2026. AI Mode switched to Gemini 3.8 Flash, starting with Pro and Ultra subscribers in English.
September 2026. AI Overviews began appearing much more often on searches for large brand names.

What brands did with their ad spend

Overall budgets barely changed. Combined spend on Google Ads, Meta, Bing and TikTok was 2% above average in September and October.

Each number compares a channel's monthly spend to its own January–August 2026 average.

Google Ads was flat in September and up 8% in October. For every brand that raised Google Ads spend, roughly one cut it.
Meta dipped in September and picked back up in October.
Bing barely moved.
TikTok went up 42% in September and 82% in October. It's still a small share of total ad spend.

FAQs

How much did Google organic traffic drop for e-commerce brands in fall 2026?
About 20%. Organic search visits in September and October 2026 were 20% below the brands' 2026 monthly average. Most of that happened at once, with a 16% drop from August to September.

Did Google release a core update in September 2026?
No. The last confirmed core update ran from May 21 to June 2, 2026. The drop lines up with changes to AI Overviews and AI Mode, especially full-screen AI Overviews in late August and AI Overviews showing up on more brand-name searches in September.

Are brands spending more on Google Ads to make up for lost organic traffic?
Not really. Google Ads spend was flat in September and up 8% in October. About as many brands cut it as raised it.

Which ad channels grew after the drop?
TikTok, up 42% in September and 82% in October compared with its 2026 average. It's still a small part of most brands' budgets.

Is lost organic traffic showing up somewhere else?
We can't say from this data. Direct traffic did jump for a lot of brands starting in August, but we haven't traced where those visits came from.

How can I tell if my store was affected?
Compare your September and October organic sessions to your own January–August average. Then check Search Console for branded queries where clicks fell but impressions held steady.

What is ThoughtMetric?

ThoughtMetric is a marketing attribution platform for e-commerce brands. It shows which channels are driving sales, so you can see where your orders come from and decide where to spend.

Can ThoughtMetric show how AI search is affecting my store?

Yes. ThoughtMetric tracks AI search as its own channel, alongside organic search and your paid campaigns. If Google clicks are shrinking, you can see whether those shoppers are showing up somewhere else. Book a demo to see it on your own data.

Methodology

We used ThoughtMetric attribution data from 200 e-commerce brands, January through October 2026. Each month's combined total is compared with the January–August 2026 monthly average, so bigger brands count for more than smaller ones.

Organic search visits are sessions attributed to the Organic Search channel. That includes Bing and other engines, though it's mostly Google. Brands with tracking gaps, partial onboarding months or one-off traffic spikes were left out.

Ad spend is platform-reported spend for Google Ads, Meta, Bing and TikTok, converted to US dollars.

Google Organic Traffic Fell 20% This Fall. TikTok Ad Spend Jumped 82%.

What happened to organic search traffic

What Google changed

What brands did with their ad spend

FAQs

Methodology

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