Ahrefs' 260M-Prompt Study Puts Reddit First and Every Mention Type Close Behind

On November 3, Ahrefs published a study of 260 million non-branded AI prompts covering 10,000 US brands. It ranks seven types of off-site mention by how closely each tracks a brand's visibility in ChatGPT, Google's AI Mode and AI Overviews. Reddit came first, at a correlation of 0.75. Domain mentions, webpage mentions and traffic-weighted webpage mentions each scored 0.70. News mentions scored 0.67, YouTube 0.64 and TikTok 0.60. Ahrefs is plain about the limits: "we can't say for certain that more mentions cause more AI visibility."

Ahrefs suggests testing Reddit and a wide spread of everyday coverage first. A CMO skimming the ranking could read that as a reason to move press money to Reddit, and the study doesn't support that. All seven types sit inside a 0.15 band, and press mentions score no higher than ordinary webpage mentions. Ahrefs' own earlier study also put a different channel on top. The data supports a narrower point. Brands that get mentioned in many places tend to show up in AI answers, and measuring your own prompts is the only way to learn which places matter in your category.

Reddit's 0.75 counts threads that already rank in Google

Ahrefs' methodology table counts only Reddit threads that rank in Google's results, so part of what the 0.75 captures is the thread's Google ranking. Threads nobody can find in search are left out entirely, which makes the metric closer to brand mentions in threads Google already rewards than to Reddit conversation in general. A team that seeds 100 new threads adds nothing to the number Ahrefs measured until those threads rank.

Ahrefs also attaches multipliers to its correlations. By its model, brands with 10x more Reddit mentions have about 5.5x more AI mentions, and brands with 10x more webpage mentions have about 3.7x more. Those are modeled figures from correlational data. They describe how brands that already have more mentions compare with brands that have fewer, and they don't estimate what a brand gets by posting or buying its way to 10x.

Brand size is the obvious confounder, and Ahrefs tested it for one mention type. Webpage mentions correlate at 0.70 across all brands, but between 0.34 and 0.54 when brands of similar search volume are compared. Large brands get mentioned everywhere and show up in AI answers everywhere, which likely accounts for a good share of the headline correlation. Ahrefs published no brand-size control for the Reddit figure, so nobody outside the company can say whether Reddit's lead survives the same test.

Press mentions, at 0.67, did no better than general webpage mentions at 0.70, and a gap that small doesn't show they did worse. Mentions on high-traffic pages also scored the same as raw counts, at 0.70, so nothing here shows a big publication beating a niche one. ChatGPT was slightly less tied to off-site mentions than Google's two surfaces on six of the seven types.

The top factor moves when Ahrefs rebuilds the study

In December 2025, Ahrefs ran a 75,000-brand study limited to brands with a Domain Rating above 40. YouTube mentions came first, at about 0.737, with branded web mentions between 0.66 and 0.71. That study didn't measure Reddit at all. The November study puts YouTube at 0.64, but the two numbers can't be read as a decline. The earlier study matched brand names as text across a different brand set, and the new one matched AI mentions as entities across 10,000 US brands. The top factor depends on how the study is built, so a budget shouldn't be reorganized around whichever factor leads the latest one.

Rival vendor Promptwatch found Reddit's share of ChatGPT Search citations averaged 3.83% from July 18 to August 7, 2026, and 0.52% from August 14 to 17. Reddit's share slipped more gently in AI Overviews, from 2.37% to 2.10%, and in AI Mode, from 2.22% to 1.54%. Promptwatch says to treat the size of the drop as provisional. Its numbers measure share of citations, which is a different thing from how mentions correlate with answers, so they neither confirm nor refute Ahrefs. Ahrefs doesn't say when its prompts were collected, so it's unclear whether ChatGPT's August shift falls inside its data.

The bigger risk to a Reddit-first plan is Reddit itself. It plans to test a logged-in-only site outside the US this quarter, and protecting its corpus is one of its stated reasons. Ahrefs notes that Reddit licenses its content to Google and OpenAI, so threads may keep feeding those engines, but on terms Reddit sets. Ahrefs' 10,000 brands are all US, and the test isn't, so this study can't show what a login wall does.

The case for Reddit is better than the top line. The median brand in the study has just eight ranking threads, and 29% have none. For that brand, Ahrefs' 10x multiplier means about 72 more threads, against 9,000 more pages in its webpage example. Ahrefs' own tracker also still ranks Reddit as the second most cited source across all three platforms, behind Wikipedia, which sits awkwardly with Promptwatch's August drop. A 0.75 correlation across 10,000 brands is strong for observational data. A thread also costs far less than a press placement, so a program with a plausible upside is worth running. That case holds if the Reddit work is funded as a test on its own budget line. It fails if the money comes out of press or content programs that the same data scores at 0.67 and 0.70. Either way, it rests on a platform where a rival vendor saw Reddit's citation share move sharply within a month.

Ahrefs sells the tracker its study points you to

Ahrefs sells Brand Radar, which tracks brand mentions across Reddit, YouTube and TikTok, and the study's section on tracking mentions points readers to it. That doesn't make the figures wrong. Ahrefs states its causation caveat more plainly than most vendor research does, and its methodology table is public.

It does show how the AI-visibility market sells. A vendor publishes a large dataset that ranks the signals, then sells the dashboard that counts them, with the dashboard using the same definitions as the study. For a GTM leader, the study is a well-built example of research doing the demand-capture work for a product.

What this means for CMOs splitting PR budget for AI visibility

Before you move any press or content money, build a fixed set of non-branded prompts your buyers would actually type, and record where your brand appears across ChatGPT, AI Mode and AI Overviews. That baseline answers the question for your category, which no cross-brand correlation can.

If you fund Reddit, give it its own budget line and a stop point in your plan, and count only threads that rank in Google, since that's what Ahrefs measured. Keep press and content programs running at their current level until your own prompt set shows a difference.

If you keep your press budget, count how many sites mention you as well as how big they are, and judge it over months. In Ahrefs' example, going from 1,000 to 10,000 webpage mentions adds only about 200 AI mentions.

Read ChatGPT results separately from Google's two surfaces. Ahrefs found ChatGPT slightly less tied to off-site mentions, and Promptwatch saw Reddit's ChatGPT citation share move within weeks, so a blended score can hide a swing on one platform.

When an AI-visibility vendor pitches its ranking of signals, ask for the brand-size control on the factor it leads with. Ahrefs published one for webpage mentions, and the correlation fell from 0.70 to between 0.34 and 0.54.

Our guess is that the next large study of this kind puts a different channel on top again. A baseline on your own prompts will still be useful when it does.

The top factor depends on how the study is built, so a budget shouldn't be reorganized around whichever factor leads the latest one.

Build a fixed set of non-branded prompts your buyers would type, record where your brand appears across ChatGPT, AI Mode and AI Overviews, and fund any Reddit test on its own budget line before moving press money.

By Business of GTM