Right now at ShopAtHome you can get toothpaste for free... or so it appears. Toothpaste is one of the items that you can get for free rather frequently with coupons. You should never pay more than $.50 for a tube of toothpaste once you start couponing/stockpiling. It might take you a few months to get into the swing of the coupon shopping style, but it's worth it in the end.
Back to why I wouldn't consider "free" toothpaste a good deal. The fine print is that you pay $1.96 up front, or out of pocket, then 30 days later you are reimbursed $1.96. While in the end it is free, the normal out of pocket cost for toothpaste is much less for couponers.
Something else to consider: You might have to wait until your ShopAtHome account reaches the $20 threshold for you to get a check and get your $1.96 reimbursed. If you do not shop online frequently, or you do and forget to use your ShopAtHome account, it might take a few months for you to see your $1.96 again.
Moral of the story is watch your out of pocket expenses!