In one line
Cost per thousand impressions: what was paid, divided by impressions, times 1,000.
A brand pays ₹5,000 for a Reel that was shown 50,000 times: its CPM is ₹100.
CPM is only as good as the impression count behind it. A figure worked out from estimated impressions is a guess, not a result.
Agree: where the impression count comes from (the creator's insights screenshot, shared access) and the date it is read.
