关于giveaway中设置促销的相关步骤和指导为您提供如下：
1.打开卖家后台进入giveaway设置界面
2.把页面拉到Offer a discount to entrants部分，点击Yes，且在下方的方框输入已经设置好的促销的promotion ID
3.对应促销的设置流程如下：
Step 1: Conditions
a) Select ‘Entire Catalog’ option under Purchased Items drop-down list.
b) Enter percentage discount between 10% and 40% for the promotion in the ‘Buyer gets - Percent off’ section.
c) Select ‘Qualifying item’ in Applies to drop-down list.
d) Enter giveaway prize ASIN as one of the qualifying items.
Step 2: Scheduling - Select the end date at least two days after your giveaway campaign is scheduled to end (9 days from now).
Step 3: Additional Options
a) Choose Single-use option for Claim Code.
b) Uncheck 'One redemption per customer' option
Click the Review button and then click Submit on the next page. Note that it takes about 4 hours for the promotion to be activated.
4.giveaway的discount to entrants促销设置需要注意以下几点：
(1)该促销是针对参加giveaway但是未获奖的参与者有效
(2)设置好的促销的折扣需要在10%到40%之间，且在接下来的9天内都要是active 的状态
(3)促销需要选择Single-use的促销码
参考页面：https://www.amazon.com/b/?_encoding=UTF8&node=11715260011
此外，对于添加到giveaway的促销，除了保证后台是active之外，还需要保证促销的截止时间必须是晚于giveaway的截止时间，即卖家的促销时间必须包含giveaway的整个时间，即整个giveaway持续的时候，促销必须是正常有效的，故active的促销并且起止时间需要包含giveaway的起止时间。
