Just because Social Network Activities aren't driving you a lot of sales doesn't mean you shouldn't leverage them. Why? Because both Google and Bing use data from social sites for them to determine how high to rank your website.
For example, Moz began to rank on Google for "Beginner's Guide" after Smashing Magazine tweeted out the guide. Shrushti moved from page 400 to page 1 of Google as a result of social networks.
To show you how social media impacts your search rankings, I decided to create a gifographic (animated infographic) that explains the correlation.
Conclusion
Whether you love or hate social networks sites like Facebook and Twitter, you have no choice but to use them. Social sites, especially Google Plus, impact your online search engine rankings.
Just take a look at the data in the gifographic above. As you can see, when one of the sites got a hundred Google Plus followers, its rankings jumped by 14.63 %. That's a huge lift.
If you would like to increase your rankings, but you don't have time to leverage all of the social sites, spend your time on Google Plus as the data shows it impacts rankings more than Twitter and Facebook.