As Lisa’s accessory business grows, her audience has expanded, too. Which Mailchimp smart recommendation tool can Sal use to make sure Lisa maintains a high email open rate?

Send Time Optimization (STO) analyzes past engagement data for each contact in an audience and recommends the best time to send an email to maximize open rates. As Lisa's audience grows and becomes more diverse, STO ensures her emails are delivered when individual subscribers are most likely to open them, thus maintaining a high open rate. Customer lifetime value (CLV) is a metric for predicting future revenue from a customer, not directly for optimizing open rates. Product recommendations suggest items to customers based on their behavior, which is for sales, not open rates. Lookalike Audience Finder helps identify new potential customers similar to existing ones, which is for audience expansion, not email engagement optimization.