In response to a post on Social Media Today:
Five Reasons Not To Have A LinkedIn Account
1) Expanding your network has no value unless you are in need of an expanded network that is based on superficial connections. Superficial connections are worth very little.
2) If you have a LinkedIn Account, as with all social media accounts you need to tend it. Having an account without using it is worse than not having one in the first place.
3) The time involved in simply "expanding your network" is often not justified unless you are job-hunting or will job hunt. For existing businesses, what you will tend to find is more businesses just like you who are looking for business themselves.
4) The spam and superficial nature of group discussions makes them, quite frankly, terrilble for learning. The smartest and brightest in your field are not likely hanging out there, unless your field is social media and marketing.
5) Who really needs those "new options"? You're already overwhelmed by this and that cool tool. Need more? Nah. Wait until you retire.