Walmart’s (WMT) Sam’s Club wholesale chain is experimenting with subscription service that permits customers to order basic consumer goods online.

The new Sam’s Club subscription service — dubbed My Subscriptions — drops shipping fees on about 700 consumer products, including diapers and office supplies. The program is meant to compete with Amazon’s Subscribe & Save program, the Wall Street Journal notes.

Amazon has been building a foothold in basic consumer products, challenging the dominance of traditional retailers. Amazon currently has between 35 million and 40 million U.S. households subscribing to its Amazon Prime subscription service, which offers free shipping on a wide range of items for $79 a year. Sam’s Club has about 47 million members.

A Sam’s Club spokesperson told the Journal that My Subscriptions wasn’t specifically aimed at Amazon. He noted that Sam’s Club is exploring various ways to expand its online sales.

The new subscription service from Sam’s Club does not include additional discounts on products purchased with free shipping. By contrast, Amazon’s Subscribe & Save program will discount orders, based on their size, up to 15%.

Sam’s Club parent Walmart has been moving to expand its online order fulfillment infrastructure in order to compete with a rising challenge from Amazon.

WMT stock climbed modestly in Friday morning trading. WMT stock has risen about 5% over the past year. By contrast, AMZN stock has gained more than 35% in the same time.