It's usually one per house, per offer. The offers usually last about 2 weeks. I usually send one to the store with Andy's name and one to the house(my name) when there's a good deal.
Here's a pretty good deal-of-the-day for Officemax:
Cendyne 4848x12x48 CDRW burner #20182491
100 pack of blank CD-R media #20187245
Telephone(wall)#20172965
Second telephone(desk) #20168453
6 pack of gel pens #20237977
FREE SHIPPING
Price for all of the above? FREE AFTER REBATES (lots of them to mail in though, one for each item)
For rebate forms and details, check out
http://www.spoofee.com
You'll have to pay the sales tax in some states, if they have a store in your state. Shipping is free.