Shopping is a social experience. Regardless of what we're buying, we're constantly looking for guidance from our friends and peers. Early on, Amazon took advantage of this and pioneered the first generation of social commerce by giving us the tools to rate and discusses products. Other retailers soon followed, and social commerce became a competitive necessity for all online retailers.
Since then, little has changed. Facebook came along and was quickly hailed as the big game changer, but its first attempts with Facebook stores failed. People were not buying products at the scale that retailers expected, and most of them dropped their F-commerce initiatives within the first year.
Press forward to today, and Facebook has just rolled out the "want" button on some very select merchants, including Pottery Barn, Fab.com, Neiman Marcus, and Victoria's Secret, as well as a few others. The concept behind the "want" button is fairly simple. Facebook users will be able to click the "want" button on partner sites and send selected products to their "want list," which is visible to the users' friends.