After GPT-5.6 launched, the share of ChatGPT Search backend requests containing the site: operator (a search syntax that restricts results to a specific domain) jumped from a long-stable 0.3%–0.5% to 16%–17%, with August 8 as the watershed. This means AI's underlying logic for finding information has changed: instead of searching the open web aimlessly, it now anchors directly to specific sites. At the same time, ChatGPT's citation share of Reddit has dropped noticeably.
What this is
Well-known tech blogger Simon Willison cited tracking data from Promptwatch (a GEO tool vendor — GEO, or Generative Engine Optimization, is SEO for the AI era) to reach the above conclusion. He further speculated that OpenAI's new search tool is structured more like search(keyword, recency, specified_site) rather than letting the AI freely choose sources.
OpenAI's August 6 official statement was a single line — "making GPT-5.6 Sol more reliable and focused" — with zero mention of underlying architectural changes. This "quiet upgrade, official silence" pattern is OpenAI's standard playbook.
Industry view
The GEO industry reacted most strongly. In the AI search era, being cited by AI is the new traffic entry point; if ChatGPT starts anchoring to specific sites, sites not "picked" could effectively disappear.
But we should also flag several risks:
First, the data source is singular. Promptwatch is just one GEO tool with limited tracking coverage; the jump from 0.3% to 16% may not reflect the full picture.
Second, the underlying logic remains a black box. OpenAI has consistently refused to disclose its system prompts (the internal rule text governing AI behavior). Simon himself can only infer through repeated testing; outside understanding is largely speculation.
Third, the drop in Reddit dependency isn't necessarily good. ChatGPT previously leaned heavily on Reddit's authentic discussions. If that dependency is cut off, whether AI answers will lose their "human feel" is a real question worth watching.
Impact on regular people
For enterprise IT: If companies want their official sites, knowledge bases, or product documentation cited by AI, they need to start thinking about "being claimed by specific AI searches," not just search engine rankings.
For professionals: People doing content, marketing, and SEO need to add a new course to their syllabus — GEO. Traditional SEO experience isn't enough; you must understand how AI picks sources.
For consumers: When regular users use ChatGPT to find information, answer sources will be more concentrated and potentially more "official," but may also become more homogeneous, losing the diverse perspectives of community discussion.