Do you still place social buttons on every page of your website? But visitors don’t like/share your content as often as you would like? You should give people a reason why they need to click social buttons on your website. Even if people really like your content, website or fanpage, they don’t click the buttons because they don’t worry about you, your benefits or your traffic. It’s not their problem.
Demo: http://codecanyon.net/item/social-locker-for-wordpress/3667715