Tomas is running a follower ad campaign. Which metric should he primarily focus on to determine the campaign’s success?

For a follower ad campaign, the primary goal is to gain new followers. Therefore, Cost Per Result (CPR) is the most relevant metric as it directly measures the cost incurred for each new follower acquired. A lower CPR indicates a more efficient campaign in achieving its objective. Average CPM (Cost Per Mille/Thousand Impressions) measures the cost for every thousand times the ad is shown, which is an awareness metric, not directly tied to follower acquisition. Reach indicates the number of unique users who saw the ad, also an awareness metric. Average CTR (Click-Through Rate) measures the percentage of people who clicked on the ad, which is an engagement metric, but doesn't confirm a follow. While clicks can lead to follows, CPR directly quantifies the cost of the desired outcome.