免费直运的商品，在商品页面 有写
Ships from and sold by Amazon.com. (fulfilled by amazon的不能免费直邮）
并且
Shipping: This item is also available for shipping to select countries outside the U.S.
需要单独寄出的不免费直邮：
"This item must be shipped separately from other items in your order. Additional shipping charges will not apply."
太大的物品也不能免费直邮：
Amazon Free shipping Offer does not apply to items larger than
18” x 14” x 8” or over 20 lbs., e-documents, software downloads, digital
music, Kindle devices and accessories, and gift cards.
祝福吗? 
