Google AI Overviews Cut Organic Traffic 10% Across 54 Brands

The traffic shift is real and measurable

Google's AI Overviews feature has reduced organic search traffic by an average of 10.5% across a portfolio of 54 advertisers, according to new data from marketing services group Brainlabs. The analysis, spanning 14 months from January 2024 to April 2025, shows total sessions dropping from 140.1 million to 125.4 million once AI Overviews began appearing on at least 30% of U.S. search results pages last September.

That September threshold marked what Sam Paez, senior manager of SEO at Brainlabs, called an "inflection point." Monthly organic traffic sessions fell from roughly 20 million to under 15 million, while referral traffic from AI platforms like ChatGPT and Gemini climbed to approximately 200,000 per month—a 163% increase during the measured period.

Why it matters

The quality of AI-referred traffic appears to compensate for lost volume. Users arriving from AI platforms completed key actions—purchases, newsletter signups, meaningful page engagement—at 1.5 times the rate of organic search visitors. AI-driven conversion events rose 335% in the study period, suggesting these visitors arrive further along in their decision-making process. For marketing teams watching traffic numbers decline, this conversion premium offers a critical counterbalance to vanishing click-through rates.

Category differences reveal strategic vulnerabilities

The impact varied significantly by sector within Brainlabs' dataset, which covered 19 industries including 16 retailers. Fitness brands, fintech companies, insurance providers, and consumer packaged goods saw the steepest traffic declines—likely because consumers research these purchases extensively before buying. Retail, beauty, and entertainment clients experienced smaller drops and some of the strongest gains from AI referrals.

Paez noted that AI Overviews trigger most frequently against educational and informational queries, though they're beginning to appear on transactional searches as well. Retailers selling products with shorter consideration cycles have been somewhat insulated so far.

ChatGPT dominates the AI referral landscape

ChatGPT accounted for the overwhelming majority of AI-platform referrals in the Brainlabs data. The disparity mirrors broader usage patterns: ChatGPT reached 1 billion monthly active users in May, while Claude registered 56 million, according to Sensor Tower.

Paez cautioned that AI referral numbers may actually undercount the channel's influence. Some AI-originated visits register as direct traffic when users open links in new browser windows rather than clicking through from within the AI interface—a measurement gap that complicates attribution.

The Brainlabs dataset included 24 U.S. companies, 24 British brands, and six clients in other markets, with 29 employing at least 1,000 staff. Paez emphasized that brands should incorporate AI referral traffic and conversion events into standard measurement frameworks and paid media planning. "We need to start taking this channel seriously," she said. "It's definitely a channel you should be including in your everyday measurement KPIs."

These findings were first reported by Digiday.