Although the past few years have been tough on retailers, Costco has managed to thrive. Not only has the warehouse club giant expanded its footprint to 914 stores worldwide, it also enjoyed a fantastic final quarter of 2025. On a year-over-year basis: Net sales grew 8% E-commerce sales increased more than 15% Membership fee income rose 14% That last point is important, because unlike other retailers, Costco relies heavily on membership fees to boost its bottom line. It's because of the membership ...