Updated by Joakim
All Ad Sets in Marketplace are prioritized based on eCPM. Ad Sets with a high eCPM has a better chance of winning ad impressions than Ad Sets with a low eCPM.
What is eCPM?
Effective cost per mille (eCPM), is the amount you pay per 1,000 views of your advertisement.
For an Ad Set with a CPM rate (cost per mille), the CPM rate is by definition identical to the eCPM value of that Ad Set.
For an Ad Set with a CPC rate (cost per click), the CPC rate is recalculated to eCPM making the rate of the Ad Set comparable with CPM Ad Sets.
How do I calculate the eCPM for an Ad Set with a CPC rate?
You can calculate the eCPM of any Ad Set using the following formula:
eCPM = Total spend / ( number of impressions / 1000 )
Consider that you only know number of clicks, impression and the CPC rate of an Ad Set you would still be able to calculate the eCPM:
eCPM = ( number of clicks x CPC rate ) / ( number of impressions / 1000 )
As you can see this is very similar to how click-through-rate (CTR) is calculated (minus the revenue) and sure enough, a high CTR and a high CPC rate will give your Ad Set a high eCPM, hence giving it higher priority in our system.
I am having trouble delivering my Ad Set on time, what can I do?
If you have defined a CPC rate for your ad set there are 3 things you can do to help speed up delivery:
- Increase the CPC or CPM rate. A higher price will increase the eCPM of your Ad Set, hence increasing the rate is the most effective measure to quickly boost delivery of your Ad Set.
- Increase CTR. As you could see when calculating eCPM for an Ad Set with a CPC rate, CTR is important in order for your Ad Set to gain priority. By increasing your CTR, e.g. by testing new images or different headlines you can gain priority without increasing the CPC rate.
- Reduce targeting. If you are targeting specific categories, locations and devices your Ad Set will be limited to placements matching your targeting criteria, hence you will not compete for as many placements. By limiting number of targeting criteria you compete for more impressions and are able to deliver your Ad Set quicker.
For Ad Sets with a CPM rate it does not help to increase CTR as it won't have any effect on eCPM. Increasing the CPM rate and reducing targeting is still effective though.