How Co-Citations Drive AI SEO

“Co-citations” in academia refer to a single research document that cites two or more sources. Yet web pages contain co-citations, too. Search engine optimizers have long suspected that Google relies on co-citations to identify similar sites.

We see evidence of co-citations on Google’s entity-based search results, such as lists of vendors and service providers.

Co-Citation and AI

With the launch of AI answers, co-citation is critical because all AI platforms — AI Mode, ChatGPT, Gemini, others — heavily on lists for brand and product recommendations. For the search “best CRM solutions,” for example, AI Overviews cite five sources. All are lists.

AI platforms rely on external lists for brand and product recommendations, such as this example of “top CRM solutions” in Google’s AI Overviews.

The sources do not have to link to their recommendations for large language models to cite them. Hence for AI optimization, co-occurrences (i.e., unlinked mentions) are as important as co-citations (e.g., linked mentions).

The less your brand appears on external websites, the lower its visibility in AI answers (and search). And the brands most commonly listed alongside yours — linked or not — define its relevance and visibility.

Search engines and LLMs may source different sites. Gauge your site’s visibility by finding, say, 20 listicles that reference your competitors. Check:

• Organic search results,
• Sources in AI Mode and AI Overviews,
• References in ChatGPT.

Many of these may overlap. But examining 20 lists will reveal your business’s relative visibility.

Several tools can help identify co-citation opportunities.

InTheMix.ai

InTheMix.ai runs related prompts in Gemini based on an initial user-generated query, analyzes the answers, and lists the sources in them. The tool, which is free, displays the number of answers for each URL (to identify the most popular).

InTheMix.ai runs prompts in Gemini and displays the number of answers for each source.

Otterly.ai

Otterly.ai is a premium tool (with a free trial) that pulls citations for any prompt from Google’s AI Overviews, ChatGPT, and Perplexity. It also provides weekly tracking of those citations to discover opportunities.

Otterly.ai pulls citations for any prompt from Google’s AI Overviews, ChatGPT, and Perplexity.

Reddit

Reddit, a top-cited source in Google and ChatGPT, is handy for researching citations of your business or competitors to know which subreddits mention your brand and competitors in the same threads.

Use AI Brand Rank’s Reddit section to analyze citations of well-established competitors.

AI Brand Rank displays citations on multiple platforms, including Reddit, shown here for mentions of “Udemy.”

Gauge Visibility

Access top platforms to compare mentions of your business or product with those of competitors. This will provide insight into your brand’s visibility in AI training data.