Why is Trader Joe's so popular?

Could you please elaborate on the reasons behind the immense popularity of Trader Joe's? Are their prices particularly competitive, or do they offer a unique selection of products that appeal to customers? Perhaps their focus on organic and natural ingredients, coupled with their dedication to sustainability, sets them apart in the retail space. Additionally, is their customer service exceptional, contributing to their loyal following? I'm curious to understand the key factors that contribute to Trader Joe's widespread appeal.