Additionally, we will have an eye on the retailer's online sales growth Costco ( COST ), the largest warehouse club in the U.S., is scheduled to release its Q1 fiscal 2014 earnings on December 11. Costco's growth is being fueled by an increase in membership base which is being driven by Volume-discount model, which is all the more attractive with the prevailing economic weakness. In the present environment, U.S. buyers have become extremely value conscious due to slow job growth, increased taxes, higher healthcare costs and high gasoline prices.