A cosmetic company noticed that its cost per mille (CPM) increased by 20% from October to December last year while running an awareness campaign on Pinterest with video and static creative. It is now reconsidering running a similar campaign this year and wants to understand what could have driven the higher CPM. What is the most likely reason for the higher CPM?

The time of year significantly impacts CPM. October to December is a highly competitive advertising period due to major holidays like Black Friday, Cyber Monday, and Christmas. Increased demand from numerous advertisers bidding for ad space drives up prices, leading to a higher CPM. More advertising inventory would typically decrease CPM, not increase it. Refreshing creative assets is a best practice that can improve campaign performance and potentially lower CPM by increasing engagement, not raise it. Increased engagement on the brand's page is a positive outcome and does not directly cause higher CPM for an awareness campaign.