Mention rate is the share of successful runs in which a model named your brand in its answer text. It is the count of successful runs where your brand was named, divided by every successful run in the window. Nothing else enters the calculation: not link counts, not answer length, not position.
What counts as a mention?
A mention is your brand name appearing in the answer the model wrote. No link is required. A model can describe you at length, recommend you, and never attach a URL — that is still a mention and it still counts. A link to your domain is a separate thing entirely, counted as a citation.
The unit of measurement is a run: one prompt, sent to one model, for one country, at one point in time. Not a reading, not an answer paragraph, not a keyword occurrence. If your name appears eleven times in one answer, that run contributes exactly one mention, the same as an answer that names you once.
How is it calculated?
Failed runs are stored for debugging but excluded from the denominator, so a model outage lowers your sample size rather than your rate. See How we collect data for what makes a run succeed.
Competitor mention rates use the same denominator — all successful runs in the window. That is deliberate, and it has a consequence worth internalising: competitor rates do not sum to 1. Several brands can be named in one answer, or none can. A window where you sit at 40% and three competitors sit at 55%, 30% and 20% is perfectly ordinary and describes reality accurately. Anything that forces those numbers to add up to 100% is dividing a fixed pie that does not exist.
Why is the API field called ShareOfVoice?
The field named ShareOfVoice in the API is your brand’s own mention rate, exactly as defined above. The name is historical and the wire contract keeps it for compatibility.
ShareOfVoice is a rate, not a share of a total. It answers “in what fraction of answers were you named?” — never “what fraction of all brand mentions were yours?” It does not sum to 100% across brands, and treating it as a slice of a pie will lead you to wrong conclusions.
How do I read the number?
Every rate arrives as {value, n}. value is the rate; n is the number of successful runs behind it. A value of null means the cell was never measured — that is not zero. A value of 0 with n above zero is a real, measured zero: the model was asked and did not name you.
Read n before you read value. At a sampling depth of one run per prompt per model per day, a single week gives you seven runs per prompt-model pair, and a rate built on seven runs moves in large steps. Reading the numbers covers small samples, deltas and unmeasured cells in detail. 
