“CVS Pharmacy stores in California are required to provide customers a $2 coupon if they identify products on store shelves that are past their sell-by date, under a settlement with the state attorney general announced Wednesday. The agreement settles claims that CVS stores routinely sold expired baby formula, over-the-counter medication and dairy products.”
Read this article or this one all about how CVS was cited by California Attorney General for selling expired goods and they settled and agreed to pay fines of close to a million dollars! The settlement also included this agreement that if customers find expired products, they will get a $2 ECB.
LA Times reports limit one $2 ECB per shopping trip, but I can't confirm that is the case. Just check with your store. Go find some 'expireds' and make CVS that much cheaper!