Now a days, social sites are working for providing the social service. For that, they work for providing the communication side for the people of world. But now a days, the social sites are working for the keywords which are posted in their users wall. They are working for improving the ranking of the keyword.
For that, social sites are the right place for doing the link building with our keywords. So, think to set a keyword before posting any kind of link and also aware about your post with a good and qualitative keyword. Set a keyword and give a short description of your link and than provide your link on the post. It works very well for improving the traffic to your website and also your income from website.