Facebook as an E-commerce Platform

Facebook is slowly becoming an
ecommerce platform for physical goods. Right now you can star the sales
process on FB, but the actual payment transaction has to happen
elsewhere. Their current strategy will be to allow for the full
ordering process to stay on site.

What does that mean? It means that organizations (who are
effectively using FB) will be able to leverage their existing fan pages
to generate sales. By keeping the transaction on site, it increases
conversion because it reduces friction.

http://econsultancy.com/blog/5672-goodbye-e-commerce-hello-f-commerce