Social Networking Guide – Linkedin, Twitter, Facebook, which one to focus on?

Quick guide on which social networking site to use for particular purposes:
1. Twitter – Use Twitter for just about everything. Find a niche and stick to it. If you’re tweeting about SEO with one persona use another for your tweets about politics.
2. Linkedin – Great for business contacts. Include all of your Facebook contacts. Never turn down a LinkedIn connection request unless it’s obviously spam. You have no idea what the person may want and the risk of connecting is pretty low.
3. Facebook – Use primarily for personal. Do you really want your business associates and potential clients seeing you in that Halloween costume? Don’t forget your friends can tag photos of you and unless your privacy settings are cranked down everyone can see those 2am pictures that sounds liked a great idea at the time.