P-score

Short for popularity score. It helps decide which channels get bundled into YouTube Select, the curated inventory Google sells to advertisers who want brand-safe placements. Reporting on it points to a handful of inputs: watch time, engagement, advertiser suitability, how much of the audience watches on a television, and production quality. It became public knowledge in 2019, when creators found it referenced in YouTube's own front-end code. Nothing about it appears in Studio and there is no documented way to raise it. Treat it as background on how the ad side sorts channels.