The news: AI search results drive more purchases, but a steep drop off in traffic may overshadow those gains, according to data from clients of marketing services group Brainlabs cited by Digiday.

• Organic web traffic for 54 Brainlabs clients declined an average of over 10% after Google’s AI Overviews (AIO) feature was rolled out more broadly in September 2025.
• Afterwards, AI traffic referral from chatbots like Gemini and ChatGPT reached about 200,000 monthly, while organic traffic sessions fell to under 15 million from about 20 million previously.
• As organic sessions fell, sessions coming from AI platforms skyrocketed 163%.
• AI-driven key events, which Brainlabs defines as visitor actions relevant to an advertiser, such as completing a purchase, increased 335% over the period measured.
• Visitors arriving through ChatGPT, Gemini, Perplexity, and Copilot were 1.5 times more likely to complete key events than those coming through organic search.

Why it matters: Brainlabs’ data is further evidence that search performance is becoming harder to judge through organic referral traffic alone, as fewer searches generate external clicks while emerging AI referrals appear to deliver relatively high-value visits.

• Other data shows the broad decrease in organic click share, which fell from 44.9% to 40% between March and June 2026, per Datos and SparkToro. That means a smaller portion of search activity is translating into visits to external websites, making organic traffic a less complete indicator of how consumers are engaging with brands through search.
• Paid link clickthrough rates drop from 13% to 6% when AIOs are present, per Seer Interactive, while 2025 publisher referral traffic decreased as much as 25%, according to Digital Content Next—showing that the traffic impact extends beyond organic links to other parts of the search ecosystem.
• July 2025 data from Pew Research Center similarly found that AI summaries nearly halve clicks to traditional search results.

Brainlabs’ data complicates the picture: AI referrals appear to offer more value per visit, but have limited scale that makes it difficult to compare their overall impact with organic search. Organic search remains a much larger web traffic source (17.1%) than genAI (0.7%), per Sensor Tower—a substantial gap that makes the overall tradeoff unclear.

Still, AI referrals’ higher key-event rates suggest that users who click through from AI platforms may arrive with stronger intent than organic search visitors.

Recommendations for marketers: The changing search landscape requires marketers to rethink what signals indicate success while maintaining focus on the channels that still deliver scale.

• Prioritize traffic quality alongside volume. Organic search still sends far more visitors than AI platforms, but traffic alone doesn’t capture the value of those visits. Marketers should compare conversions, key events, revenues per visit, and other downstream outcomes across referral sources.
• Invest in AI visibility, but don’t abandon SEO. AI referrals are growing in value, but their small share of web traffic indicates that, for the time being, marketers need to build visibility within AI-generated answers alongside, not in place of, their current search strategy.

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