Free shipping: offer free shipping on the products when customers purchase a certain number of units or dollars
Money Off: offer certain price discounts on the products when customers purchase a certain number of units or dollars
Buy One Get One: offer free items to customers when they purchase certain products
External Benefits: offer certain post-order benefits to customers
Free Shipping, Money Off, and BOGO are the most effective promotions for customers because customers can enjoy the savings immediately at checkout.