Whole Foods Market, which was purchased last year by online retail titan Amazon, is stealing market share from some retail chains, according to a new study.

In more than 100 markets, Whole Foods stores are gaining foot traffic at the expense of Trader Joe’s, Walgreens and Dollar Tree stores, according to a study by Los Angeles-based Sense360 cited in a Bloomberg story.

Whole Foods has been successful in luring shoppers at stores within a mile of Whole Food stores with the promise of discounts via Amazon Prime memberships, according to the story.

Sense360’s chief executive officer, Eli Portnoy, tells Bloomberg that while national grocers aren’t hurting yet from Amazon’s purchase of Whole Foods, Amazon is getting traction at the “micro” level. “We’re at the very beginning stages, and these things take time. These findings show there will be an impact.”