I got this in my e-mail. It says one-time use, but I don't think that means only one person can use it. They probably mean you can use each coupon only once.

http://reg.cheetahmail.com/c/s/tagfrm/hBGsYECAFtjc1BTg0t5ABnAAK3W/coupon.html?n=30&email=&MEDIA_TAG7=100059346