I believe they are an island. It's called Social for a reason. As a noun according to the dictionary,social means a social gathering or party. As an adjective it is the interactions of people.
So why on social media channels are some people just tooting their own horns and not being social? Maybe they are newbies or don't realize they can engage their followers more with give and take. Help them out. Share their content. You never know who will share your content or tweet next.
Of course it should be content you can relate to; or believe in. Not just any content. That would be fake. Just be yourself and have fun. I've recently noticed some businesses sending tweets to competitors tooting their own horns - what is up with that? Would that be called black hat social networking?
Even if you are on a social network for business, you should enjoy socializing with others. If you are a newbie its fine to watch for a while but please join in, get off that island and let's get social. They are called Social Networking Sites for a reason.