AI Search Engine Optimization has published its latest AI Answer Benchmark, measuring which firms six major AI platforms recommend when buyers research AI search services and which external sources appear in those answers. The open benchmark also publishes its question set, measurement window, answer counts, and methodology so the findings can be reproduced and compared over time.
More details are available at https://aisearchengineoptimization.com/ai-answer-benchmark-september-2026/
The report arrives as AI assistants move deeper into consumer research and purchasing decisions. Interactive Advertising Bureau research published in September 2026 found that 72% of consumers surveyed use general-purpose AI assistants for shopping-related decisions, illustrating how closely AI-generated recommendations are moving toward the point of purchase.
That growing role creates a measurement problem, says founder Phil Belleville noting that “AI visibility is not just about whether your website ranks.” Recommendations can change by platform, question, location, and measurement date, making isolated screenshots or visibility scores difficult to interpret. AI Search Engine Optimization says its benchmark is intended to replace those anecdotal signals with a repeatable measurement process.
The September measurement covered 26 buyer and research questions across ChatGPT, ChatGPT Web Search, Google AI Overviews, Google AI Mode, Gemini, and Bing Copilot during the seven days to September 16. It recorded 247 brand mentions involving 18 firms.
The source analysis showed that agency service pages were largely absent from the material AI platforms cited most often. Google documentation appeared in 21.7% of captured answers, followed by YouTube at 16.7%, while a review directory appeared in 9.7% and community threads in 8%. No agency service page reached the benchmark's 10 most-cited sources.
Visibility was concentrated on the brand side as well. The three most-named firms appeared in 53, 42, and 35 answers respectively, across a field of 18 firms. For businesses tracking AI search visibility, the agency argues that repeated recommendations across different buyer questions provide a stronger signal than an isolated appearance.
Crucially, the benchmark publishes the full question set, six platforms tested, seven-day measurement window, and denominators behind its percentages. It also leaves AI Search Engine Optimization's own lower position visible in the table. The firm says this disclosure is intended to make the findings reproducible rather than present the benchmark as a promotional ranking.
About AI Search Engine Optimization
AI Search Engine Optimization is an Omaha, Nebraska-based AI SEO agency for WordPress businesses founded by Phil Belleville, who has worked in SEO since 1995. The firm works nationally and uses its Rank Intelligence Engine to measure and improve AI search visibility across traditional search and generative engine optimization.
The full method and results are available at https://aisearchengineoptimization.com/ai-answer-benchmark-september-2026/