Answer: Segmentation by usage
Explanation: Segmentation by usage splits customers according to how often they use a product. Using segmentation by usage, customers can be classified into non - users, who don't use the product at all, light and medium users, who can range from little usage of the product to average use of the product, and heavy users, who mostly use these products.
From thr first paragraph it is clear that usage segmentation is used to separate the user's into different classes based on their usage, and identify which class to target when it comes to sales. At Estelle Cosmetics Company, it was deduced that of this company's total sales, less than 7% of this market are heavy users. These users purchase nearly 71% of the company's products. This company will probably focus their marketing efforts on the heavy users, as they contribute to the majority of sales within their company.