Set product tier price as a percent or as a fixed discount of its price, mass update tiered prices
Create BOGO (Buy one, get one) promotions within the cart price rules.
Create promotions that allow discounting the cheapest / most expensive item in the cart.
Edit in Cart
Edit product options in the cart, without leaving or reloading the cart page.
Auto-add a free gift to the customer cart. Let the customer select his free and discounted products directly from the cart...
Create an infinite variety of promotions and coupons - BOGO (Buy One - Get One), Product bundled discount, Quantity step (Each Nth) and much more!