从今年3月开始book seller可以自己设置运费，这是真的不？

是真的，不过这只是针对专业账号，对个人账号影响不大：
We are making three important changes for sellers who sell Media products on the Amazon Marketplace on Amazon.com: 
1. Sellers will be able to offer free shipping and set their own shipping prices on Books, Music, Video, and DVD products.（从2017年3月1号开始，对于媒介类产品，卖家可以提供免邮、以及设置自己店铺的运费）
Effective March 1, 2017, you will be able to set your own shipping prices for Standard delivery and set different shipping prices by region for Expedited, Two-Day, or International delivery. Your current shipping settings and shipping prices will be retained when the new capability launches on March 1. Beginning on that date, you can adjust your shipping prices for Books, Music, Video, and DVD products using Shipping Settings.
2. Sellers will be able to compete for the Buy Box for Books in new condition.（如果卖家卖的是新书，那他们将有资格竞争buybox）
Starting in late Q1 2017, eligible sellers will be able to compete for the Buy Box for Books in new condition. The Buy Box is the display on the product detail page with the Add to Cart button that customers can use to add items to their shopping carts. When one of your listed items appears as the default on the product detail page, you win the Buy Box, which can increase your chances of selling that item. To compete for the Buy Box, both your selling account and your listed item must be eligible. Becoming eligible to compete for the Buy Box doesn’t guarantee that you will win it. You can increase your chances by pricing your items competitively, offering Prime and free shipping, providing great customer service, and keeping stock available.
3. Changes to Selling on Amazon fees.
We will be making two changes to how Selling on Amazon fees are charged for Media products (including Books, Music, Video, DVD, Software, and Video Games). These fee changes will not take effect until March 1, 2017, to give you time to plan accordingly.
Variable Closing Fees (VCF): The VCF charge in Media product categories (Books, Music, Video, DVD, Software, and Video Games) will increase to $1.80 from $1.35 per item. This charge will appear as a Closing Fee (CF) instead of as a VCF to avoid confusion, as it will be a fixed fee rate and not variable.（从3月1号开始，媒介类产品的VCF将由$1.35增加到$1.80。[注：”VCF”将变更为”CF”；同时，它将是一笔固定费用]） 
Referral fees: Currently, the referral fee for Media products is an applicable percentage of an item’s sales price (excluding any shipping or gift wrap charges). Effective March 1, 2017, the referral fee will instead be calculated on the total sales price (the total amount paid by the customer, including the item price and any shipping or gift wrap charges), as follows:
①Books, Music, Video, DVD, Software, Video Games (non-console)
Current Fees: $1.35(VCF); 15% of the item price(Referral Fee)
New Fees: $1.80(CF); 15% of the total sales price(Referral Fee)
②Video Game Consoles
Current Fees: $1.35(VCF); 8% of the item price(Referral Fee)
New Fees: $1.80(CF); 8% of the total sales price(Referral Fee)
（目前媒介类产品的佣金算法是：佣金=产品本身的价格[不包括运费和礼品包装费]×15%或8%；而从3月1号起，媒介类产品的佣金算法变为：佣金=产品总价格[包括运费和礼品包装费]×15%或8%）
For additional information on Selling Fees, please see the Selling on Amazon Fee Schedule.