I’m loving my new Green Bag Tag from CVS!  What a brilliant idea!  There is a CVS across the street from my home and office so I’m a frequent shopper there.  For just $1 I purchased my GBT.  Each time I shop and either use a re-usable bag or no bag at all, they scan my Extra Care card and then my GBT.  After 4 visits I get $1 cash back coupon to use on my next purchase!  The actual tag is even made from a corn based material.  I know it is somewhat of a hassle to have to lug around one more card to scan but you could attach to it your key ring or loop it through the handle of your reusable bag.