Sellers can help improve customer experience by offering free shipping that customers love, which could in turn help attract new customers, and may increase a seller’s chance of winning the Buy Box. For more information, visit Winning the Buy Box.
There is no sign up involved. To offer free shipping on your products, simply go to Shipping settings and set your shipping rates to $0.00.
You can change the shipping rate you want to charge by updating the rates in your shipping template.
For information regarding Amazon fees, including examples, visit the Selling on Amazon Fee Schedule page.