I think of SL as a step beyond Facebook and Twitter. Twitter and Facebook have a pretty high signal to noise ratio, I find myself spending more time skimming and less time reading, and easily distracted. In a SL conversation, it draws my focus and I carefully read what the person types, and trend shut out the noise, like in the real world, face to face. Maybe it is me, but you get some basic body language in SL. It is crude, but at least if they are standing there looking at you, I feel like they care enough to listen. With other social media, it is more of yelling and hoping they or anyone hears.
 
http://allin1panel.com/blog/12-unheard-ways-achieve-greater-social-media-marketing/