clipped from www.techipedia.com

Forgetting that some individuals won’t network with you on a “personal” space like Facebook without knowing who you are, even with the proper introduction. If you’re looking to establish a professional relationship with someone, consider LinkedIn. Otherwise, consider building up a rapport with an individual before randomly adding them as your friend. Some people require face-to-face meetings before they invite you into their private lives. After all, Facebook was a tool that college students were using before it was open to the public, and some still use it as a purely personal and not a professional tool. LinkedIn is still seen as the more professional of the two.