Over two posts on his blog, Ron Tite has written a crash course for corporations using social media. They work really well as a case study for best practices. The main point: let compassionate humans run your social media, not your legal department, not your marketing department. Be genuine; have character; and engage your audience instead of yelling at them, deaf to their responses.
One of the most common mistakes big brands make is using social media as a one-way bugle that provides a never-ending and piercing stream of infomercial-like offers, deals and promotions. On both Twitter and Facebook, Pizza Pizza excels at this. SM isn’t a commercial. It’s an operational service that listens, responds and keeps people interested and engaged.