AI Search: Perplexity, Google AI Mode, ChatGPT Search — 2026-09-27
This week: BrightEdge data shows ChatGPT now sends 95.1% of all AI referral traffic, while Comscore data reveals ChatGPT losing 20 points of US AI prompt share to Gemini and Claude. Perplexity faces a new trade-secret lawsuit over voice tech, Google's publisher traffic decline steepened to 40% year-over-year, and a DOJ document argues copyright suits against AI companies should be widely dismissed.
AI Search: Perplexity, Google AI Mode, ChatGPT Search — 2026-09-27
Top developments
ChatGPT reaches record 95.1% share of AI referral traffic
BrightEdge data released September 24 shows ChatGPT referral traffic more than doubled from January to August 2026, reaching a record 95.1% share of AI referral traffic to websites — roughly 22 times the combined share of Gemini, Claude and Perplexity. Meanwhile, Claude referral traffic fell 15% and Perplexity fell 17% in August. For anyone tracking AI answer engines, the "referral war" is effectively a one-horse race, with major implications for where publishers should invest visibility efforts.
Comscore: ChatGPT loses 20 points of US AI prompt share to Gemini and Claude
A Comscore-based analysis published this week finds ChatGPT has lost 20 percentage points of US AI prompt share to Gemini and Claude. The same data notes sponsored ads reached 47% of ChatGPT video-game chats by June, while Google AI Overviews covered 39.4% of Google desktop searches. The divergence — shrinking prompt share but surging referral dominance — suggests ChatGPT monetizes clicks better than competitors even as rivals gain users.
Google search decline steepened to 40% YoY for publishers
A Chartbeat-based report covered September 24 finds Google Search and Discover declines steepened to 40% year-over-year for publishers, with losses growing even as direct, internal and dark-social traffic grows. Separately, German outlet AD HOC NEWS reported the same 40.2% figure and noted studies showing fewer external clicks inside AI Mode. This is the strongest signal yet that AI Overviews' traffic toll is accelerating, not plateauing — fuel for ongoing EU and CMA proceedings.
Perplexity sued by voice-tech startup DaVoice
A startup, DaVoice, sued Perplexity AI alleging the company used a promised partnership to extract proprietary wake-word technology — the code that recognizes spoken activation phrases — and then built its own system with it. Perplexity called the lawsuit "baseless," saying it involves standard wake-word technology as used in devices like Amazon's Echo. It adds to Perplexity's mounting legal docket, which already includes copyright suits from The New York Times, CNN and Britannica/Merriam-Webster.
DOJ document argues AI copyright suits should be widely dismissed
The Atlantic reported on September 25 that an overlooked DOJ document argues copyright suits against AI companies should be widely dismissed, a shift with big consequences for the NYT, CNN and Britannica cases against Perplexity and dozens of other disputes.
Local view
German-language coverage this week centered on publisher losses: AD HOC NEWS highlighted the 40.2% Google Search/Discover traffic decline and a separate finding that 98% of software-review searches now show AI answers, with classic review-site search volume down a median 50%. The Economic Times in India covered the DaVoice–Perplexity suit, noting the complaint cites DaVoice's proprietary source code, inference logic, and training data.
Context & numbers
- ChatGPT referral share of AI traffic: 95.1% (August 2026), per BrightEdge
- Sponsored ads: 47% of ChatGPT video-game chats by June; AI Overviews on 39.4% of Google desktop searches (Comscore-based analysis)
- Publisher traffic: −40% YoY from Google Search/Discover (Chartbeat-based)
- 86% of AI best-product answers cite a commercial source; affiliate-heavy outlets like TechRadar and Forbes Advisor lead across 106,758 AI citations analyzed by GetCited
On the radar
- The DaVoice v. Perplexity trade-secret case is at filing stage; early motions could reveal more about Perplexity's voice-product roadmap
- Watch for reactions from publisher plaintiffs (NYT, CNN) to the DOJ's dismissive copyright stance
- GetCited's 25.4% sourcing figure has drawn scrutiny given the author sells article placements — treat commercially-linked AI-visibility data carefully
This content was collected, curated, and summarized entirely by AI — including how and what to gather. It may contain inaccuracies. Crew does not guarantee the accuracy of any information presented here. Always verify facts on your own before acting on them. Crew assumes no legal liability for any consequences arising from reliance on this content.
Powered by
