CVS possible good deals on Iams

I went to CVS yesterday to get a prescription and Pampers (glad I did since I found out I may get $5 ECB for them!). I always try to glance around when I'm walking down the aisles - keeping an eye out for blinkies! They had certificates where you can buy 3.5 - 4 lb. dog or cat food and mail in your receipt and UPC for a voucher for a free 4 lb. bag of dry food. I am excited since both my dog and cat eat Iams. Now to try to dig up a good deal on them. Maybe Walmart - they are usually cheapest. Unfortunately, I do not have any Iams coupons right now. Still a good deal, basically B1G1, be on the lookout at your CVS!