CPM stands for cost per mille, which means cost per thousand impressions. It is a unit of measurement used in online advertising to calculate the cost of an ad campaign. CPM is calculated by dividing the total cost of the campaign by the number of impressions served. For example, if a campaign costs $100 and serves 10,000 impressions, the CPM is $10.
eCPM stands for effective cost per mille. It is a more accurate way to measure the cost of an ad campaign because it takes into account the value of each impression. eCPM is calculated by dividing the total revenue generated by the campaign by the number of impressions served. For example, if a campaign generates $100 in revenue and serves 10,000 impressions, the eCPM is $1.
The main difference between CPM and eCPM is that CPM only measures the cost of an ad campaign, while eCPM measures the revenue generated by an ad campaign. This means that eCPM is a more accurate way to measure the effectiveness of an ad campaign.
It is important to note that both CPM and eCPM are just metrics, and they do not tell the whole story about the effectiveness of an ad campaign. Other factors, such as the quality of the ads, the targeting of the campaign, and the conversion rate of the campaign, also need to be considered when evaluating the effectiveness of an ad campaign.