The user doesn’t come out of nowhere. We don’t land on your page and then head happily to those social networks to promote you, just because you have a button on your site. We find content through Facebook, Twitter, Google , Pinterest etc., not the other way around.
Whoever uses social networks to find content, usually begins the web journey there and goes back naturally. We don’t need to be reminded of what network we use on the way. We know. We came from there.
For those who don’t use social networks the social media buttons are completely useless.
If readers are too lazy to copy and paste the URL, and write a few words about your content, then it is not because you lack these magical buttons.”
Sweep the Sleaze | Information Architects
I hardly ever use share buttons when I tweet or post a link to my news feed. However, when I do use them, I find them slightly more convenient than when I have used a “share” bookmarklet in my browser (which is how i share the majority of my content).