CPM (cost per mille, i.e. per thousand impressions) is the standard way video advertising is priced. An AVOD or FAST service's ad revenue is essentially impressions x CPM x fill rate, so CPM is one of the three levers that determine whether ad-supported economics work.
CPMs vary enormously by content quality, audience targeting, device (connected-TV CPMs are typically much higher than mobile web), geography, and ad format. Premium, well-targeted, brand-safe inventory commands higher CPMs, which is why measurement, targeting data, and viewability matter: they directly raise the price advertisers will pay per thousand views.
