Facebook and LinkedIn are two different social networking tools. They both have their strengths and weaknesses for both personal use and in a professional environment, but I don’t think of them as interchangeable.
LinkedIn provides more of an individual resource and job network. Connections are formed based on (hopefully) prior knowledge of a person’s strengths with work related talents. Personally, I try to never connect to someone I would not recommend IRL for a job or support their claims in their professional field. I use this resource as quality over quantity; however I am not sure that everyone has that same standard. Getting ready to enter a new career field, I can very much see the benefit in stretching my network beyond my current connections.
Facebook is a fascinating platform. It can informative and an easy to use marketing tool for businesses. They can list everything from daily specials, to hours of operation, to upcoming events. This makes it a very attractive network for libraries and even special library programs. Personally, it can be a quagmire of relationship ties and past lives. (Uh no Facebook, I’d rather NOT be friends with my ex-boyfriend’s sister who tried to poison my milkshake in high school… I’ve sort of moved on, but thanks for asking) The advertisements make it a bit less appealing for a broad audience but normally the ads are not questionable.
My new school, IUPUI (go Jaguars!) uses Facebook well. They update frequently but not too frequently. Information is timely and well presented. Topics they post are mostly neutral and reflect what is happening at the school.
With any social networking, it is important to know your audience, know your platforms strengths and weaknesses and to maintain your site so that it is fresh and appealing and user friendly.