Additionally, tracking the amount of ancillary income a group brings to the hotel is beneficial: did they use the outlets, gift shops, parking, valet, etc.?

另外，对一个团队为酒店所带来的辅助性收入进行检测是大有益处的：他们是否有逛商场和礼品店、停车和使用个人助理等？

youdao

Purchasing any new product or gift card on an auction or classified advertisement site where the price is significantly lower than any sale prices in retail outlets.

FORBES: FBI To Holiday Shoppers -- Be Wary!