I wrote a quick post about this for the Digital Gateway Blog, and will provide the bullet points here, with a few other thoughts.

Why should your library invest in another social media outlet?

• It’s free: The only cost is staff time.
• It’s, possibly, the next big thing, so getting in early shows how savvy your library is with technology trends.
• Greater capabilities than Twitter: Honestly, 140 characters is ridiculous. People that are tied to the 140 character mentality seem quaint.
• Greater capabilities than Facebook: Circles are great. Focus content to users that want it. Facebook doesn’t allow “pages” to create lists. Content suffers from the megaphone effect and comes across as noise.
• It can act as a blogging platform: Users can link to individual posts.
• Hangouts: Give users an opportunity to connect with staff (reference questions?) or view exhibitions.
• The Google platform: Google+ ties in to other Google services. Leverage them for your benefit.

Sure there are only 10 million users on Google+, so maybe it’s a bit early, but do you have anything to lose, and can you afford to wait?