Store-exclusive brands increasingly appeal to consumers, particularly in these cash-strapped times. Sam's Club offers Member's Mark products to shoppers, which is an exclusive brand featuring grocery staples, attire, decor, cleaning supplies, alcohol, and more. While consumer preferences vary according to all sorts of factors, including personal tastes, Costco is generally considered the leader among warehouse retail chains when it comes to private label brands. For example, the store has reported that its popular Kirkland Signature brand brought in a whopping $58 billion in 2023. That same year, Sam's Club's Member's Mark line reportedly earned an approximate $25 billion. It's not entirely clear why Costco's Kirkland Signature brand is such a sales juggernaut when compared to Member's Mark. Sam's Club exclusives get plenty of love from customers, both for affordability and quality.