At a Glance

1. 1Display CPM — the actual pricing and billing unit for display campaigns: cost per 1,000 impressions, set via Maximum CPM and Dynamic CPM bidding.
2. 2Video CPM — a reporting-only metric for video campaigns: cost per 1,000 video impressions (starts). Video campaigns are not billed on CPM.
3. 3Video's real billing event is CPV — cost per completed view, meaning at least 10 continuous seconds watched.
4. 4Because the two CPM figures measure different inventory with different price floors, they should never be compared directly.

How Display CPM Works

For display campaigns, CPM is both the pricing model and the billing unit. You set a Maximum CPM — your bid ceiling per 1,000 impressions — and Topple's Dynamic CPM bidding participates in real-time auctions on your behalf, paying the lowest price needed to win each impression, up to that ceiling. The CPM your reports show for a display campaign is a direct measure of what you actually paid to reach 1,000 people.

How Video CPM Works

Video campaigns are not billed on CPM at all — they're billed on CPV (Cost Per View), meaning you're charged when a user watches at least 10 continuous seconds of your video, not per impression. Your video reports still show a CPM figure, calculated as cost per 1,000 video impressions (video starts) — but that figure is there for cross-campaign reference only. It is not the billing event, and it is not directly comparable to a display campaign's CPM, which is the actual price paid per 1,000 impressions.

The Practical Difference

A display campaign's CPM is the price you're paying, full stop — it's both the bid mechanism and the billing outcome. A video campaign's CPM is a derived reporting number that happens to use the same formula (cost divided by impressions, times 1,000), but it doesn't represent what you're actually being charged for — CPV does. Two campaigns with identical CPM figures, one display and one video, are not equivalently priced or equivalently efficient, because they're billed on entirely different events.

When to Use Each Metric

1. 1Use Display CPM to evaluate and compare the efficiency of display campaigns against each other — it's a true apples-to-apples price comparison within display.
2. 2Use Video CPV, not video CPM, to evaluate the actual cost-efficiency of a video campaign — it reflects what you're really paying for.
3. 3Use Video CPM only as a rough reference for reach efficiency within video, or to sanity-check reporting — never to compare against a display campaign's CPM.
4. 4Use VTR (View-Through Rate) alongside CPV to judge whether a video campaign's creative is holding attention, not just how much each view costs.

Common Mistakes

1. 1Comparing a video campaign's CPM directly against a display campaign's CPM to judge which is 'cheaper' — they're calculated the same way but represent different billing events on different inventory with different price floors. This comparison doesn't tell you anything meaningful.
2. 2Optimizing a video campaign toward a lower CPM — since video isn't billed on CPM, chasing a lower video CPM can mean chasing cheaper, lower-quality video starts rather than actual view completions. Optimize toward CPV and VTR instead.
3. 3Assuming a video campaign has no CPM figure at all — video reports do show a CPM, calculated the same way as display's, but it's informational only, not the billing unit.

Related Troubleshooting

1. 1
   Why aren't my ads getting impressions? →

Next Steps

1. 1
   See every metric defined in Understanding Your Metrics →
2. 2
   Adjust your Maximum CPM bid ceiling →
3. 3
   Review CPM, Dynamic CPM, and CPV in the Glossary →