How marketers can identify gaps in AI search citations

Marketers assessing their search visibility may need to look beyond conventional keyword rankings, according to a HubSpot guide on answer engine optimization, or AEO. The guide describes an AEO keyword gap as the difference between the questions AI answer engines address and the topics a brand covers clearly enough to be cited. Finding those gaps can help teams identify where competitors appear in AI-generated responses while their own brand does not.

The distinction from traditional SEO is the unit of analysis. A standard keyword gap compares the terms for which competing companies rank. An AEO gap also considers questions, prompts and broader topics, with attention to whether an answer engine cites one brand rather than another. HubSpot identifies ChatGPT, Gemini and Perplexity as examples of engines where marketers can examine these differences.

The guide places the issue in the context of buyers using AI to evaluate products. Rather than receiving a page of links, a buyer asking for a recommendation may see a paraphrased answer or a shortlist. A brand that does not appear in responses to questions relevant to its category can therefore be absent from that initial set of options, even when the question concerns a product or solution it offers.

HubSpot says its research covered 3,063 people involved in CRM software purchasing decisions and found that 42% of CRM buyers use AI search during evaluation. The company also describes AI search use as the strongest predictor of purchase intent that it tracks. Separately, the guide cites Search Engine Land’s finding that referral traffic from AI tools such as ChatGPT and Gemini has tripled over the past year.

HubSpot’s proposed workflow begins with an audit of a brand’s existing content alongside competitor coverage. Teams can then identify citation opportunities they are missing, decide which gaps merit attention first and develop content intended to provide clear answers. The guide also recommends tracking progress over time to assess whether the work is improving visibility in AI responses. Its broader point is that content coverage and citation opportunities should be considered alongside conventional rankings.

What this means for marketers

Use competitor comparisons to examine both search rankings and the questions for which AI engines cite sources. Start with gaps relevant to the brand’s category, review whether existing content answers those questions clearly, and track changes after updating or creating content. This gives teams a way to assess AEO work rather than treating an appearance in a single AI response as the whole measure of progress.