CPM

CPM is what you pay for one thousand impressions of your ad.

The M is the Latin mille, a thousand, so CPM reads as cost per thousand times your ad is shown. It is a delivery metric, not a results metric. It tells you how expensive it is to put your creative in front of eyeballs, whatever those eyeballs go on to do.

Say TikTok charges you 90 rupees to show your ad three thousand times. Your CPM is 30 rupees, because ninety split across three thousand impressions, then scaled to a thousand, lands at thirty. Tight targeting and crowded auctions push it up, broad reach pushes it down.

A low CPM can flatter a bad ad. Cheap impressions mean nothing if nobody clicks or buys, so a rock bottom CPM sitting next to a dead conversion rate is a warning, not a win.

CPM measures exposure, not persuasion.