How does the Special Offer "Buy 2 DVDs, Get 1 Free" work?

When you add 3 DVDs to your shopping cart, the amount of the least expensive DVD will automatically be discounted from your total. There is no limit to this discount. For every two DVDs you buy, you can add another one free: buy 4 and get 2 free. The discount will be applied to DVDs of lesser value first. Multi-DVD sets and bundles count as one product. The free DVD must be added to your cart at the time of purchase.