Right now at Walgreens, you can buy one, get UNLIMITED FREE Gatorade Prime and Recover.
Here's how it works:
Buy one 20oz bottle of Gatorade Prime (approx $1.70), and a coupon will print for a FREE bottle of Gatorade Prime and Recover. Use that coupon to purchase another, and ANOTHER coupon will print out for a free bottle and so on and so forth.
No known limits on this one, except any that may be set by your own store.