How should product marketers measure brand visibility in AI search?

How should product marketers measure brand visibility in AI search? We’ve been exploring how brands show up across AI platforms like ChatGPT and Perplexity, and how this is changing the way buyers discover and evaluate products. As AI-driven discovery grows, traditional SEO metrics may no longer tell the whole story. For product marketers, what metrics do you think matter most when measuring AI visibility:- share of voice, brand mentions, citations, sentiment, or something else? Curious to hear how others are approaching this and whether AI visibility is becoming part of your marketing measurement framework.