We connect with our old friends and make new friends on Facebook. Once we meet a new person and find him or her interesting, the social conversation ends with "Ya sure, We'll meet on Facebook". This is followed by knowing the other person through his or her Facebook profile and occasional chats. Chats represent a medium that develop relationships to a more intimate level. While we chat or converse with friends, we disclose about ourselves. In our initial conversations, we disclose about the outer layers of our personality such as work, hobbies, music etc. If the other person finds us interesting, the conversation proceeds by reciprocity of disclosure since disclosure begets disclosure. A chat provides a more conducive environment for disclosures because of limited cues. These limited cues and the discomfort of a face to face conversation are minimized by this medium. Going ahead with disclosure, as a person's disclosure is reciprocated there are feelings of intimacy. This intimacy fosters the connections between two individuals at a more emotional level. So from being a mere acquaintance, you become friends and the intimacy might even rise to a sexual level. This phenomena has been observed since the late 1950s at a face to face level and has been studied and verified in a computer mediated environment in 1990s. But there is a catch. Disclosure does not always beget disclosure. If you disclose too much, too soon, you'll end up scaring your partner away. You have to do it gradually within the social norms.
So if you are looking to build a relation with someone at a more intimate level, use chat because it is more private and helps you disclose more. And if you are looking to be an attractive person all your friends, you need to disclose more on your Facebook profile.