Many shoppers are leaving money on the table by ignoring the various loyalty programs offered by their favorite grocery stores. These programs are designed to reward your regular shopping habits with points that you can exchange for free products. Some chains even offer a free item every single month just for being an active member of their rewards list. It only takes a minute to sign up, and the rewards can be quite significant over a full year. Here are seven rewards programs that make it easy to earn free groceries.