Second Measure analyzes credit card transactions. In their analysis they found that just 20% of customers were responsible for more than 50% of the revenue for the top 1000 companies they have transaction data available.
The average top 20 customer spends 8x more than the average bottom 80% customer.
I found this super interesting because I’ve seen this myself in my companies. I always wondered if this was normal and at times felt some apprehension about it since a large portion of the business was carried by a relatively small number of customers. Apparently this is normal.