US warehouse chain Costco Wholesale (NASDAQ:COST) announced on February 1 local time that sales in January increased by 6.9% year-on-year to $16.84 billion, but e-commerce sales fell by 15.4%. In the 22 weeks ending Jan. 29, Costco sales rose 7.5 percent to $99 billion, with same-store sales up 6 percent.