A Cost Per Mille (CPM) is an equation that works out the total ad spend per 1,000 impressions on one site.
An impression occurs when the ad is displayed and seen by the target audience. So, a CPM is when a company has to pay for their ad every time 1,000 people that are within the target audience, see it.
This information is normally found in business record sheets. It is a good figure to analyse how well the business is performing.
