Topical Authority Boosts Brand Visibility in AI Search

Brands demonstrating topical authority in one category have a significant chance of being cited in adjacent or even distant categories within AI search results, according to an analysis of AI Visibility Toolkit data. This suggests that establishing expertise in a core area can indeed broaden a brand's visibility across a wider range of topics, though the nature of this expanded presence shifts from direct mentions to citations.

The study, which utilized data from Semrush's AI Visibility Toolkit covering approximately 1,000 categories from January to June 2026, involved three primary tests. The "relatedness test" examined how often a brand appeared in new categories after having already appeared in at least three out of five prompts within a related category. The "future performance test" tracked brand mentions and citations over a six-month period to assess long-term impact. Finally, the "breadth vs. depth test" investigated whether brands focusing on a wide array of topics experienced any detriment compared to those concentrating on depth within fewer topics.

Data from Semrush, encompassing 1,094 categories and five prompt variants per category, revealed that while brands can achieve citations outside their established expertise, they are less likely to earn direct mentions in these new domains. A "small but robust effect" indicates that brands which "own" a particular category are more successful in expanding their reach into other areas. However, the topical authority effect does not manifest uniformly across all industries, suggesting that the competitive landscape and industry-specific dynamics play a crucial role.

Crucially, the research highlights that a category is not truly "won" until a brand earns repeat mentions, signifying a deeper level of recognition and authority beyond mere citations. The breadth tests, drawing on 283,215 citations and 76,493 named-brand-mention observations, paired with subsequent monthly outcomes, underscore the importance of sustained presence. The relatedness test, specifically, analyzed 45,578 expansion appearances by 1,458 mapped brand entities, providing quantitative evidence for the transferability of topical authority. This implies that a strategic focus on building deep expertise in core areas can serve as a powerful engine for broader brand recognition in the evolving AI search environment.