The default location of the share buttons leaves a lot to be desired. On a full page of posts, you have to scroll through 20 posts to even see the share buttons. Furthermore, on the home page, they are at the bottom of the sidebar.
If you have altered where your share buttons show post up where you have them.
Same as above i also disabled the stock share buttons in favor of something that better met my preferences..
I've since re enabled the default share options in order to put a advertisement in the header. But the buttons were very successful in the header when they were there..