CPM (cost per mille)
What advertisers pay for 1,000 ad impressions. It is not what the creator earns: that is RPM.
CPM is the price side: how much advertisers pay per 1,000 times their ad is shown. It changes with the season, the audience’s country and the topic of the video.
Creators earn a share of it, spread over all their views, including views that showed no ad. That share per 1,000 views is RPM.
Estimate what your Shorts could earn
Try it