Costco's sales for August increased by 9.9%. This growth occurred despite higher gas prices. The company also experienced digital growth, which contributed to the overall sales increase.

Further details about Costco's August sales performance are available from Chain Store Age. The publication reported on the sales growth, noting the impact of higher gas prices and digital growth.

For more information about Costco's sales and the factors that influenced their growth, readers can refer to the original report from Chain Store Age.