While all e-commerce sites need to be able to support search, catalog browsing, and checkout, what really distinguishes one site from another is how it is able to continuously evolve towards giving customers a better, more fulfilling buying experience. Who participates in the decisions about the direction of that evolution? The customer of course! How does that evolution occur? Through the process of 1) A/B testing to continuously solicit customer feedback through clicks and purchases, and 2) through continuous improvement of customer search and recommendation to improve the relevance of products that are offered to the customer.