help page for the new program has the fine print: "With free shipping, your order will be delivered 5-8 business days after all your items are available to ship, including pre-order items". Even though over half of all U.S. households now have Prime memberships, Amazon would undoubtedly like to convert even more consumers to paid subscribers.
While Amazon's offer notably doesn't include two-day shipping, the e-commerce giant appears to be relying on its much larger assortment of goods to draw in customers.
Even so, the program could get expensive for the company.
Amazon isn't the only merchant slashing shipping fees. During the fourth quarter of 2017, the company spent a record $7.3 billion getting packages to customers. There's a feature called AR View, for example - a new augmented reality feature in the Amazon app that allows customers to view products in situ before they purchase.
On Monday, Amazon returned fire, saying it will eat the shipping costs on "hundreds of millions" of items on its online bazaar during the holiday rush.
Amazon's plan could overshadow holiday strategies from top competitors like Target, which offers free two-day shipping on all orders from November 1 to December 22.
Amazon has insisted new offers will emerge "as often as every five minutes", meaning those who want the best offers will need to stay glued to the site.
Some customers were already seeing the option on Sunday evening. In both cases, the advantage over Amazon was no paid subscription required to qualify for free shipping.
The promotion will make hundreds of millions of items eligible for free shipping, Amazon said.
Walmart offers free two-day shipping on sales of more than $35, while Amazon's free delivery-window guarantees are limited to members of its $119-a-year Prime program.