To serve social ads. We occasionally pair advertisements we serve with relevant information we have about you and your friends to make advertisements more interesting and more tailored to you and your friends. For example, if you become a fan of a Page, we may display your name and profile photo next to an advertisement for that Page that is displayed to your friends. We only share the personally identifiable information visible in the social ad with the friend who can see the ad. You can opt out of having your information used in social ads on this help page.

We do not own or run the applications and websites that you interact with through Facebook Platform, and while we try to enforce standards to protect your information, we cannot guarantee that they will follow our rules. 

Examples of the types of information that applications and websites may have access to include...on Facebook: your name, your profile picture, your gender, your birthday, your hometown location (city/state/country), your current location (city/state/country), your political view, your activities, your interests, your musical preferences, television shows in which you are interested, movies in which you are interested, books in which you are interested, your favorite quotes, your relationship status, your dating interests, your relationship interests, your network affiliations, your education history, your work history, your course information, copies of photos in your photo albums, metadata associated with your photo albums (e.g., time of upload, album name, comments on your photos, etc.), the total number of messages sent and/or received by you, the total number of unread messages in your in-box, the total number of "pokes" you have sent and/or received, the total number of wall posts on your Wall, a list of user IDs mapped to your friends, your social timeline, notifications that you have received from other applications, and events associated with your profile.