I never saw this before,
https://smile.amazon.com/gp/help/customer/display.html?nodeId=GTJVA73QBN37CYVE&pop-up=1Extended Free Shipping by Amazon
FREE Shipping on any eligible order placed within 24 hours of your qualifying order.
To qualify for Extended Free Shipping, place a $25 order consisting of items shipped by Amazon and select FREE Shipping during checkout.
Once you place a qualifying order, you can use Extended Free Shipping for the next 24 hours without an order minimum. To use Extended Free Shipping, add eligible items to your cart and select FREE Shipping during checkout.
Canceling items, combining orders, or changing your shipping address, speed, or preference might affect your free shipping eligibility.
Restrictions
Only items shipped by Amazon are eligible.
Orders must be shipped to the same address as your first order.
For special products or orders, an additional handling fee may still apply.
Geographic shipping restrictions may apply. Some items shipped to Alaska, Hawaii, and Puerto Rico may not be eligible.
For information about international free shipping to eligible addresses, visit International Free Shipping.
