Dive Brief:

• Costco says its same-store sales rose 6% in May, topping analyst forecasts of a 4.6% rise.
• The company operates 657 warehouse stores around the world. Global same-store sales rose 7%, as U.S. sales rose 4%.
• The big box discount retailer also announced plans to open six more locations before the end of its fiscal year in August.

Dive Insight:

Costco is doing quite well this year even as its rivals struggle to get their footing. For the first quarter, Costco saw its revenue rise, whereas rival Wal-Mart continues to warn of trouble ahead.

Of course things may look quite different soon if Amazon's attempt to compete against the warehouse clubs gains any traction.