Facebook CPM: what it is
T
he Facebook's CPM (or Cost Per Thousand Impressions) is a very important metric that defines the cost of obtaining 1000 'impressions' or views of an ad within the platform. It is therefore a true KPI, a value to be taken into strong consideration when analysing and monitoring Facebook ads. Understanding this metric makes it possible to assess the effectiveness of a campaign and, consequently, to intervene for any changes or corrections. In this regard, however, it is worth making a few clarifications. The cost of 'impressions', in fact, must not be confused with the cost of obtaining clicks on the ad. In the first case, in particular, the metric refers to the people who viewed the Facebook ad. In the second case, on the other hand, the value to be considered is the 'Cost per Click' (CPC), which indicates the cost necessary to obtain clicks on the ad. On the other hand, a user may simply view the ad without clicking. On the other hand, he or she may deepen the campaign by clicking on the ad and landing on a landing page.
Facebook CPM: how it is calculated
The formula for calculating the CPM is therefore as follows:
Ad price/Number of contacts reached X 1000
Consequently, if an ad cost €500 and the campaign reached an average of 100,000 people, the CPM would be €5. The absolute value, however, is not very indicative. To assess this metric correctly, it is in fact necessary to compare several values obtained from campaigns in the same sector or business field. Not only that, the CPM may also vary according to the selected audience or depending on the format and graphics chosen for the advertisement. In short, before assessing the goodness of this indicator, it is good to consider a number of parameters, to have an average CPM as a reference and, above all, to fully understand its usefulness.
Facebook CPM: what it is used for and how to reduce it
To do this, it is necessary to start from the purpose of this metric, which is to indicate the cost of obtaining a certain number of 'impressions' or views of an ad. The weight this value has within a campaign therefore depends on the objective of the campaign. If, for example, the purpose of the advertisement is the mere display of the ad, then this KPI will play a key role. Conversely, if the goal of the campaign is to get more clicks to a landing or website, then the CPM will be of relative importance. In fact, an advertisement could get a lot of views and thus have a low CPM and at the same time receive few clicks. Consequently, if a campaign is aimed at increasing visits to the site, the CPC, i.e. the 'Cost per Click', will have to be considered above all. On the other hand, the CPM may play an important role in advertisements that aim at company awareness and thus brand awareness.


Facebook CPM: how to optimise it
In the latter case, the advertiser's goal will be to lower this cost as much as possible, through a series of changes and interventions in ad management. One of these is to make good use of the placements offered by Facebook. In particular, the 'automatic positioning' function should be used when setting up the campaign, so as to allow the platform to direct the ad to the best channels. In this way, a low CPM can be achieved. Another winning strategy is to A/B test as much as possible.
This means creating several adverts with different creative, so as to identify the most effective one that can lower the cost of views. Finally, the best way to reduce the CPM is certainly to create a full-funnel strategy, starting with the creation of campaigns that aim to increase brand visibility, i.e. to increase the number of ad views.