Cost per mille viewable impressions (vCPM)

vCPM or CPVM goes one step further than Cost per mille (CPM) / effective cost per mille (eCPM) in that the advertiser only pays for every 1,000 viewable impressions – i.e. those that were actually seen by the user.

Further reading:

• The AdTech Book by Clearcode: Advertising Basics
• The AdTech Book by Clearcode: Chapter 08. Tracking and Reporting Impressions, Clicks, and Conversions in AdTech Platforms
• What Is Ad Verification and How Does It Work?