In answer to Amazon’s Prime Service, Walmart has cut the delivery time of its ShippingPass e-commerce subscription program to two days rather than three.  

This program, which is still in a pilot phase, offers customers  free delivery of more than 1 million products on the site.

The company’s delivery  model is to use its stores and distribution centers to support its online efforts. Over the holiday season, the company encouraged shoppers to place orders on its website and pick the products up in stores.

“We can offer faster and more affordable shipping because we have a unique fulfillment network that includes new large scale fulfillment centers, stores, distribution centers and our transportation network,” Walmart said in a statement released on May 12.

The company has been investing in new technology and has grown its online sales last year to $13. 7 billion, according to Investor’s Business Daily.

However it is still facing challenges. According to Investor’s Daily its revenue has shrunk 1% year over year in each of the last two quarters, and its diluted earnings per share has contracted for four quarters in a row.

Meanwhile, Amazon continues to grow sales at a double-digit quarterly rate and posted a $1.07 per share profit last quarter, reversing from a loss of 12 cents a share during the same period in 2015.