Customer cohort is a group of customers who share something in common - in ecommerce, it’s usually the product, campaign, coupon or source of their first order. Such segmentation is useful to monitor how these factors impact the shopping behavior and loyalty of customers over time.
That’s why customer cohorts are the basis of cohort analysis. It compares various cohorts to identify which products, marketing channels, offers, etc. convert the best leads who later become the most loyal customers. Thus, you can adjust your marketing and improve your retention rate and other retention metrics.
Other benefits of monitoring customer cohorts:
Here's how cohorts by product bought look in Metrilo:
on Metrilo blog