If you spot these specially marked Arm and Hammer Baking Powder boxes, might as well grab them. This is on the 1lb boxes which are priced around $.50 at many stores. I actually bought this one for $.62 at Target but my store doesn’t carry the 1lb size anymore.
You can try Walmart too.
You just need (2) boxes of baking soda- on the back of the box is a little form to fill out. Include the UPC numbers from the boxes and a copy of your receipt and you should get a 1 year subscription to the magazine for free.
This is while supplies last but it doesn’t expire until May of next year. I still think it is best to send off for these things as soon as you can.