"We feel more confident about it this year than we have in the last couple of years," said Richard Galanti, the company's executive vice president and chief financial officer, during Costco's Q1 conference call. During the quarter, which ended Nov. 30, Costco opened a total of nine new stores, eight in the US and one in Mexico.

Next year's fourth quarter will see the most store growth, when 14 new units are planned. Two are planned for the second quarter and about six are to opening the following period.

During the most recent quarter, same-store sales rose 9% from the same year-ago period. That included November, when Costco's 6% increase was below competitor Sam's Club's 7%, the first time it had fallen below the Wal-Mart chain for many months. Galanti says Sam's Club's spike was due to a national print advertisement by the chain. "We like it when our competitors do national print advertisements," he said, explaining that such efforts work well initially but later run out of steam.