Retention is usually measured by the customer retention rate, which is the percentage of people who make repeat purchases from an e-commerce store.
Platforms like WooCommerce and Shopify have plugins that automatically display your customer retention rate.
However, if you need to work it out for yourself, the calculation is as follows:
[(A-B)/C] x 100
A = the total number of customers you ended up with.
B = the number of new customers you won.
C = the total number of customers you started with.
Subtract the number of customers you won during the period from the number you ended the period with. Divide that by the total number of customers you started with, then multiply by 100 to get your retention percentage.
For example, an online clothing store wants to calculate its retention rate for Q1 of the year.
In January, they had 100 customers (C).
At the end of March, they had 110 customers (A).
Between January and March, they won 30 new customers (B).
[(110-30)/100] x 100 = 80
Between January and March, this clothing store maintained an 80% retention rate. Not bad at all.