What key aspect does conversion rate measure in a digital marketing campaign?

The conversion rate is a critical metric in digital marketing as it quantifies the effectiveness of a campaign by measuring the percentage of visitors who engage in a desired action. This action can vary depending on the campaign's goals, such as making a purchase, signing up for a newsletter, or downloading a resource.

This metric is essential for understanding customer behavior and the overall success of marketing strategies. A higher conversion rate indicates that a greater proportion of visitors find the campaign appealing and compelling enough to follow through with the desired action, signifying effective messaging and targeting.

The other aspects mentioned, such as the cost of advertising, total number of social media posts, and the amount of feedback collected, do not provide insight into the effectiveness of influencing visitor behavior towards a specific action, which is the primary purpose of measuring the conversion rate.