Ask ChatGPT which project management tools it recommends for a growing agency, and you'll get a shortlist, not an exhaustive list. Maybe three names, maybe five. If your brand is one of them, you're capturing a piece of a conversation that never touches a search results page. If it isn't, a competitor is capturing that buyer's attention instead, and you have no idea it happened. AI share of voice is the metric that turns that invisible gap into a number you can actually track, and it's the core metric that LLM brand visibility tools like Branviz are built around.