Average Purchase Frequency counts the average number of transactions per customer per period. This metric is used to better understand customer behavior and purchase patterns.

Customer Retention Rate calculates the proportion of customers in a particular period that are retained into the next period.

Email Reply Rate measures the percentage of sent emails that generate a reply. This metric is crucial for assessing the effectiveness of email marketing campaigns, customer engagement, or team communication efforts. Higher reply rates typically signify that the content of the email is resonating with the audience, prompting them to engage in the conversation. However, it's important to keep in mind that various factors can influence Email Reply Rate, including the quality of the email content, the subject line, and the relevance to the recipient.

Lift in Spend is a loyalty metric that calculates the increased spend per customer or groups of customers across two periods.

Transaction Recency measures the duration of time since a customer’s last purchase, indicating how recently repeat customers made previous purchases. It is a great way of measuring your business’s ability to bring back customers quickly and may vary based on industry and business model.