It's no secret that Walmart and Amazon are bitter rivals. While the former is the undisputed brick-and-mortar king, Amazon's online dominance is unrivaled. But in an attempt to boost its e-commerce presence, Walmart today announced a new unlimited shipping program. For $50 a year, half the cost of Amazon Prime, Walmart online shoppers can get free shipping in three days or less. Codenamed Tahoe, the shipping service is expected to roll out later this spring on an invite-only basis. Free Shipping on Over a Million Products — But What Other Perks? According to the National Retail Federation, Walmart is the biggest retailer in the country, dwarfing industry giants like Target, Costco, and Amazon. However, as more consumers switch to online shopping, Walmart wants to ensure it remains in the dominant position. Currently, the company offers free value shipping (six to nine days) on purchases of $50 or more. Under its new plan, customers will get 3-day shipping for $50 a year. Although that's a day slower than Prime, it's considerably cheaper. However, Walmart's new service doesn't include any additional perks, like the free video and music streaming options, that Amazon provides. That's not to say Walmart can't entice consumers with perks of its own. Walmart owns Vudu, an on-demand digital video service. And last year it introduced the Vudu Spark, a Chromecast-like dongle for streaming video from its Vudu service. In terms of what products will qualify for free shipping, the company says the service will apply to over a million items, including toys and electronics, during beta trials. Currently, Walmart offers over 7 million products for sale online. As with most shipping programs, items sold through the retailer's marketplace will not qualify for free shipping. The Free Shipping Landscape With its latest move, Walmart joins an ever-growing club of retailers with free shipping services. Back in February, Target announced it would offer its customers free shipping on orders of $25 or more. That's $10 under Amazon's minimum and $25 under Walmart's threshold. And last year, Newegg also introduced its own shipping program called Newegg Premier, which for $50 per year offers complimentary 3-day shipping. Will you try out Walmart's new shipping program? Or will you stick with another online retailer? Let us know in the comments below. Related DealNews Features: More Than Free Shipping: 8 Perks to Amazon Prime E-Retailers Offered More Free Shipping Last Year, But Can it Continue? POLL: Will Target's New Free Shipping Pull Customers From Amazon?