MAC Cosmetics offers a MAC lipstick of your choice for free when you return six MAC primary packaging containers via post or to a MAC Cosmetics counter as part of its Back to MAC Program. That's the first such offer we've seen from MAC, yielding a savings of at least $16. (Plus, you even get to choose your preferred lipstick shade.) Eligible packaging containers include empty eyeshadow cases, lipstick tubes, powder compacts, foundation bottles, and more.