Costco Wholesale Corp.

Shoppers are picky about their grocery stores — and they should be. Most consumers spend a significant amount of time every week at their stores of choice gathering food to feed their families.

While Walmart and Kroger are still the No. 1 and No. 2 retailers in the United States, despite the nation’s recent economic woes, a new slate of companies are starting to come on strong, according to STORES Magazine’s annual ranking of retailers by sales.

The vitamin, mineral and supplement (VMS) market is now about $11 billion in the United States, according to TABS Group, Inc., a Shelton, Conn.-based research and consulting company, which added that the category had grown by approximately 20 percent since the last time it did an estimate, in January 2008.

Over 30,000 shoppers found Costco to be the best of 11 of America’s most popular chain stores, a survey by Consumer Reports has found.

Costco Wholesale Corp. posted a 46 percent increase in quarterly profits.

A shopper experience study currently underway by the Integer Group and M/A/R/C Research has found that 60 percent of shoppers look for coupons before going to a store.