Facebook Sponsored Stories is the new feature will be added in near future. If you like an item or brand in Facebook, you click on Like button and it appears on your profile… this is the old story you had with you. But now, with FB sponsored stories, you can become a promoter of that product or brand which you clicked like and appear on your friends’ pages as advertisement. Directly you can recommend your friend to buy that product (in the sense of Facebook).
This new idea of Facebook may become begin a threat for Google Adsense. Google is already worrying about the popularity of Facebook as its number of users is exceeding the number of Google’s users. FB has 600 million active users.