Reddit’s ChatGPT Search citations drop 86% in August, raising questions about AI traffic fragility

Reddit went from being one of the most-cited sources in ChatGPT Search to barely registering at all. In the span of about seven days, the platform’s share of citations plunged from 3.8% to 0.5%, an 86% relative decline that started around August 8. The culprit appears to be a modification to ChatGPT’s query fanout behavior, a backend change by OpenAI that altered how the AI expands user queries and ranks the sources it pulls from. What happened and how fast it happened Data tracked by PromptWatch paints a stark picture. From July 18 through August 7, Reddit averaged roughly 3.83% of all ChatGPT Search citations. Then around August 8, citations began falling off a cliff. By August 14, the average had cratered to 0.52%. The August 14 through 17 window confirmed the new baseline wasn’t a blip. The timing lines up with a change in how ChatGPT handles what’s called “query fanout,” the process by which a single user question gets expanded into multiple sub-queries to pull in a broader set of relevant sources. When OpenAI tweaked that mechanism, the sources that benefited from the old expansion logic lost their advantage overnight. This isn’t Reddit’s first algorithmic rodeo Reddit has be...