Citation share is the proportion of cited sources in AI answers for a given topic that point to your domain rather than to competitors or third parties. Where share of voice counts brand mentions in the text, citation share counts the source links the AI attributes its answer to.
For brands, citation share shows whether your own pages are doing the work of grounding AI answers, or whether the AI is leaning on third-party sources instead. A low citation share alongside decent visibility often means others are being cited to describe you, which points to a content or authority gap on your own site.