Definition
AI share of voice contextualises mention rate against the competitive set. A 60% mention rate is bad in a category where the #1 brand has 95% - and excellent in a category where the #1 has 65%. Use it as a relative, not absolute, KPI.
Why it matters
Share of voice (AI) sits in the "Measurement" layer of the AI search stack. Teams that handle it well get cited more, recommended more, and earn more of the AI-mediated revenue in their category. Teams that ignore it spend a year wondering why their content investment never moves the needle inside ChatGPT or Perplexity.
Related terms
- Mention rate - The percentage of prompts in a defined panel where an LLM names your brand. The headline metric of LLM SEO programs.
- Citation share - Percentage of cited sources in an LLM answer that come from your domain. Only meaningful on grounded surfaces (Perplexity, ChatGPT Search, AI Overviews).
- Rank in answer - Where your brand appears in an LLM's ordered recommendation set - first paragraph (best), middle, or final mention (weakest).
Apply it
The LLM SEO playbook ties every concept in this glossary into a single operating model. If you want to see how your brand performs across all the LLMs at once - mention rate, citation share, sentiment, rank - start with the free GEO audit or skip straight to a free Livesov account.