Although executive members make up 47.3% of Costco's membership, they account for more than 70% of the company's total sales, the retailer reports. During a May earnings call, Costco CEO Ron Vachris said the company is exploring ways to improve the shopping experience amid complaints about overcrowding, long checkout lines and limited parking. "It is a strategic priority for all of us in the company right now to continue to look at how we improve the member experience in our high-volume warehouses," he said. Vachris added that opening new locations in densely trafficked areas could help reduce congestion at some stores.