Mailchimp's Content Optimizer gives additional guidance with analysis based on industry best practices. Access this feature in the new email builder or your email campaign reports before sending your next email.
Originally, when Facebook launched its ad algorithm, it was based on an auction which meant it gave priority to the highest bid. However, in 2018, Facebook announced it shifted toward the user experience model while integrating the auction. The auction is based on different aspects of how ads are served to users on the platform.
