We continue our series of conversion tips from Charles Nicholls, founder and CEO of SeeWhy, a conversion and cart-abandonment-recovery firm. For this tip, Nicholls addresses shipping charges, and surprises, in the shopping cart checkout process.

Charles Nicholls: "Nothing adds to customer frustration more than getting hit with unexpected shipping and handling costs late in the checkout process. In a recent Forrester study, one in five consumers stated that they had abandoned shopping carts because shipping costs were not shown on the product detail page. While this isn't by any means the biggest cause of shopping cart abandonment, it is certainly very annoying for customers. It also distorts your conversion rate numbers as it suggests...