O'Reilly is an aftermarket automotive parts retailer in the United States and Mexico with nearly $16 billion in annual sales. The company operates over 6,000 domestic stores and serves both the do-it-yourself (about 55% of sales) and professional (45% of sales) end markets. Despite operating amid a highly fragmented industry, O'Reilly differentiates itself by providing quality service to its customers throughout the entirety of the vehicle diagnosis and purchasing process. Furthermore, the firm boasts an impressive hub-and-spoke distribution network designed to provide its localized store base with ample aftermarket product availability across a variety of vehicle makes and models.