hi, i’m amr. a lot of teams hear “Reddit is the most-cited source in AI search” and start a Reddit plan the next morning. before you do, look at what happened to that number in a single six-week stretch.
the swing nobody planned for
Semrush tracked about 230,000 prompts across ChatGPT search, Google AI Mode and Perplexity, with weekly snapshots from July 14 to October 12, 2025. That is 13 weeks and more than 100 million citations. In early August, Reddit showed up in close to 60% of ChatGPT’s prompt responses. By mid-September it was around 10%.
same platform, same prompts, six weeks apart. nobody’s content got worse in that window. the engine simply changed what it leans on.
what the data does and doesn’t say
- Reddit didn’t disappear. it and Wikipedia stayed ChatGPT’s two most-cited domains, and Reddit remained in the top five on all three platforms.
- the drop was concentrated in ChatGPT. Wikipedia’s shares on the other platforms stayed stable, so this was a platform-specific shift, not a market-wide one.
- the cause isn’t established. one theory pointed at Google dropping its num=100 parameter. Semrush’s Sergei Rogulin doubts that, noting only about 34% of Reddit’s roughly 263M ranking keywords sit in positions 21-100, and says he believes the main reason is an attempt to avoid over-citing certain sites.
one caveat from my side: this is 2025 data, and the engines have moved since. i’m using it for the pattern, not for the percentages.
why a single-source plan is fragile
if your AI visibility plan is “get mentioned on one site,” you are betting on a decision made inside someone else’s product. when the weighting shifts, you find out from a traffic dip, not a warning. a plan spread across several kinds of sources absorbs that kind of change. a plan built on one source doesn’t.
what to do instead
- build a fixed prompt set. write down 20-30 questions your buyers actually ask, and run the same set every week so a change in the engine shows up as a change in your own log.
- log by platform, not in aggregate. record, for each engine, whether your brand appears and which domains get cited next to you. an average across engines would have hidden the ChatGPT swing completely.
- spread your footprint. keep answer-first pages on your own site, then add third-party presence in more than one place: review sites, trade press, YouTube, LinkedIn, community threads. Semrush’s own advice is to find the domains AI tools trust in your niche and build relationships with them.
- treat community as one channel, not the strategy. participate where your buyers genuinely ask questions, but don’t let a single forum carry the plan.
how this connects to the stack
Semrush’s AI visibility tools are built for exactly this weekly tracking, and it is worth reading the same prompt set against your classic rankings. in GA4, watch referral sessions from AI assistants as their own segment, and pass that source into HubSpot so you can see whether those visitors become qualified pipeline or just traffic. the point is to measure your own exposure per platform instead of trusting a headline about who is cited most.
where this stops applying
if your buyers never discuss your category in public forums, a community push was never going to be your main lever, and the swing matters less to you. the diversification argument still holds, though. one source, one platform, one algorithm is a thin base for anything you are counting on.
start scaling — if you’re not logging where AI assistants cite you, a fixed weekly prompt set is the cheapest place to start. let’s connect.
Sources: Semrush, “Most-Cited Domains in AI” study (about 230,000 prompts across ChatGPT search, Google AI Mode and Perplexity, weekly snapshots July 14 to October 12, 2025; percentages are approximate as reported). Figures are published industry research, not verified results from Amr’s own client accounts.