Promptwatch, a company operating in the Generative Engine Optimization (GEO) space that provides tools and consulting to help sites increase visibility in chatbot replies, says it observed a notable change in ChatGPT Search usage. Promptwatch’s product automates tracking of prompt responses across end‑user chat products such as ChatGPT, Claude, and Gemini, and it publishes aggregate reports based on that tracking.
What changed?
According to Promptwatch, the share of ChatGPT Search fanout queries that included the site: operator was stable between 0.3% and 0.5% for weeks. That share briefly dipped to 0.15% on August 3–5 (which Promptwatch characterizes as consistent with a staged rollout or pre‑launch experiment), and then jumped to about 16–17% on August 8.
These figures apply only to the prompts for which Promptwatch has automated tracking enabled and therefore do not necessarily represent all ChatGPT queries.
Timing and ties to OpenAI’s update
The timing of Promptwatch’s observation coincides with OpenAI’s August 6 announcement that they were updating GPT‑5.6 Sol in Chat for Plus and Pro users to be “more reliable with facts and provide more focused answers.” Because OpenAI obscures system prompts, Promptwatch and outside observers can only infer the nature of internal changes.
From hands‑on probing of ChatGPT, the latest search tool appears to be structured more like a search(query, recency, domains) call rather than explicitly encouraging use of a site: operator in prompts.
Follow‑up: less Reddit sourcing
In a follow‑up on August 18, Promptwatch reported that ChatGPT appeared to have substantially reduced the likelihood of using Reddit as a source in those searches. Attempts to verify whether the system prompt was updated to discourage Reddit sourcing have so far been unsuccessful; the most comprehensive leaked collection of system prompts known to date does not show clear changes related to this.
Why this matters
Metrics like these can reveal otherwise invisible product design decisions and rollout effects inside chat‑based search systems, information that is valuable to GEO practitioners and site operators aiming to influence how content appears in chatbot replies. However, because the data come from a single tracker’s automated sample and OpenAI does not publish detailed internal changes, causal conclusions remain tentative.
Summary
Promptwatch’s automated tracking shows a sudden rise in site: operator usage in tracked ChatGPT Search queries in early August, coinciding with the GPT‑5.6 rollout. While Promptwatch also reported a later reduction in Reddit sourcing, independent confirmation of system‑prompt changes is currently lacking.
