Repeat Customer Insights has included a customer grading algorithm for awhile now to help translate the complex RFM model into something easier to understand.
Since it uses five segments, it's also useful for small Shopify stores who don't need or want a complex model.
I've just released a new Customer Grading Report for the app that will summarize how your customers are graded by the algorithm.
This combined with the grading details for each customer should give any Shopify store the ability to get started segmenting customers.
If you haven't tried Repeat Customer Insights yet, it comes with a 14-day free trial so you can see how it helps before paying.
Eric Davis
Get a complete view of your customer behavior
The cohort analysis in Repeat Customer Insights will automatically build cohorts for all of your customers. It has the ability to go back through your entire store history so you can get a complete view of your customer behavior.