Share of Voice in AI Overviews: Measuring Competitive Brand Presence

Share of voice (SOV) has been a cornerstone metric for advertising and organic search. In traditional search, SOV is the percentage of impressions your brand receives relative to the total addressable impression pool. For AI-generated overviews, the definition shifts. Impressions are not countable because AI platforms do not serve ranked listings with trackable exposures. AI SOV is the percentage of AI-generated responses in which your brand is mentioned relative to the total mentions of all competitors within a defined query set.

This shift from impression-based SOV to mention-based SOV requires a different measurement approach but delivers comparable strategic value. Brands that dominate AI overview mentions are the ones users encounter when they ask generative platforms for recommendations or comparisons in a given category.

The AI SOV formula is straightforward: AI SOV = (Your brand mention count) / (Total brand mention count for all competitors in the query set). The mention count includes every occurrence across all probe queries. To prevent a single query from skewing results, the count is capped at one mention per query per brand.

The competitive set must be defined before measurement begins. For a project management software brand, the competitive set might include Monday.com, Asana, ClickUp, Notion, Jira, and Trello. Each brand is tracked across the same probe queries.

A comprehensive benchmark published by BrightEdge in Q1 2026 analyzed AI overview SOV across 12 verticals using queries run against ChatGPT, Perplexity, Gemini, and Claude [1]. In the software and SaaS vertical, the top three brands captured 62 percent of all AI overview mentions. The remaining competitors split the remaining 38 percent. This concentration is higher than organic search SOV for the same verticals, where the top three typically hold 45 to 50 percent of impressions.

For e-commerce and consumer goods, concentration was lower at 41 percent for the top three, likely because AI models tend to list multiple options for product comparisons. The study also found high week-over-week stability at 85 percent or more for established brands, unlike organic search results that fluctuate with algorithm updates.

Three factors correlate with above-median AI SOV. Documentation density matters most. Brands with extensive, well-structured technical documentation appear at significantly higher rates. Independent review volume also drives SOV, as training data and retrieval corpora conflate review authority with general brand authority. News cycle presence provides a temporary boost: brands covered by major publications within the last 30 days show a 15 to 25 percent SOV increase over baseline [2].

A brand may hold 40 percent SOV on Perplexity but only 15 percent on ChatGPT for the same query set. Perplexity emphasizes web retrieval and source citation. Brands with strong web presence and backlink profiles perform better there. ChatGPT, especially for non-browsing sessions, relies more heavily on training data. Brands with extensive Wikipedia and media coverage see higher SOV in ChatGPT. Gemini sits between the two, applying stricter source authority thresholds.

A quarterly AI SOV tracking cadence is appropriate for most organizations. Monthly tracking introduces noise from model updates and retrieval corpus refreshes. The minimum viable system requires 30 to 50 probe queries per competitive set, executed against all major AI platforms within a 24-hour window to avoid temporal bias. The mention capture and extraction pipeline can be automated using LLM-based parsing that maps brand names to the predefined competitive set [3].

Define your competitive set with 5 to 10 direct competitors. Build a probe query set of 30 queries representing the highest-volume search intents in your category. Execute against ChatGPT, Perplexity, and Gemini. Compute AI SOV for your brand and each competitor on each platform. If your SOV is below 15 percent on any platform, investigate the documentation density and news presence gap between your brand and the top performers. Address the most actionable gap first and re-measure in 90 days.