From Smashing Magazine:

Here is the harsh reality of e-commerce websites: according to recent e-commerce studies, at least 59.8% of potential customers abandon their shopping cart (MarketingSherpa puts it at 59.8%, SeeWhy at 83% and MarketLive at 62.14%). The main question is why do customers abandon their shopping cart so often? Is there some fundamental mistake that designers of e-commerce websites do very often? Are there any common guidelines or rules of thumbs that make it more difficult for our users to purchase products? And is there some meaningful way to improve the conversion rates for our products?

Well, that’s exactly what we wanted to find out. In 2010, we recruited a batch of Web users and conducted a usability study, focusing only on the checkout user experience, from “Cart” to “Completed order.” The study was conducted using the “think aloud” protocol and was documented by recording everything that happened on the computer screen. The behavior of the test subjects was then analyzed by scrutinizing these recordings at a later date.

The study has shown that it is often difficult to lead customers to the final step in the checkout process when the only thing left is to submit their credit card details.

The 15 e-commerce websites that we tested were: 1-800-Flowers, AllPosters, American Apparel, Amnesty, Apple, HobbyTron, Levi’s, Newegg, Nordstrom, Oakley, Perfume.com, PetSmart, Thomann, Walmart and Zappos.

In total, the test subjects were given more than 500 usability issues, ranging from being distracted by animated graphics to being thrown off course by an illogical checkout flow. These issues were then analyzed and distilled into 63 checkout usability guidelines in a report titled “E-Commerce Checkout Usability.” In this article, we’ll share 11 fundamental guidelines from that report with you.

Read the rest here.