The company releases its sales data on a monthly basis, which takes some of the mystery out of its upcoming Q3 report, which it files May 25. But when you factor out the impact of gasoline-price deflation and foreign exchange, the numbers are close to, albeit slightly under, the company's year-to-date increases. If this translates into a reduction in membership numbers this would be problematic for Costco, and could signal further issues to come after the June 20 deadline date hits.