Wal-Mart's latest offer takes on Amazon Prime

The retail giant's promotion of ShippingPass is its latest effort to become more competitive in the ecommerce space.

Wal-Mart on Wednesday announced the nationwide launch of ShippingPass, its direct challenge to Amazon Prime. A free, 30-day trial of the two-day shipping program is now available across the US, while existing customers will get a free month of the service.

ShippingPass launched in a few cities last year, but it's now available nationwide for just $49 a year, which is half the price of Amazon Prime.

Although Wal-Mart has performed relatively well as far as brick-and-mortar business goes, it's still heavily investing in ecommerce. The retailer reported last month that first quarter ecommerce sales grew 7 percent, but CEO Doug McMillon said "growth here is too slow".

The company is turbo-charging its ecommerce business largely through its online grocery ordering and pickup service. Earlier this month, Wal-Mart announced it's partnering with Uber, Lyft, and Deliv to begin testing last-mile grocery delivery services.

The company is also growing its ecommerce business abroad. Last week, Wal-Mart announced a new partnership with JD.com, China's second largest ecommerce company.