Social Media Signals help in Search Engine Ranking?

We have a website with social signal of Google+, Facebook & twitter on our home page. I understand that for getting higher ranking on the search engines the Facebook likes & +1 that are receive for this page will help me in search engine ranking. I have a sister concern company which has its own social media profile. Which will be better for my site for search engine rankings?

A. a like that I received from social media profile of my sister concern
B. a like received from dedicated social media profile of my own website.
C. Both are same.

Please suggest us…

Any “like” or “+” will help, but in very small amounts. I have at least hundreds, possibly a couple of thousand, and Google analytics still don’t measure them as a significant factor. “Important” sites get hundreds per page, multiplied by dozens of pages.
As with most seo issues, it does’t pay to try to work out how to squeeze the last drop out of it; it will either work, or it won’t.

How many pluses you have on your blog, that affect your search engine rank. Also facebook likes and twitter give traffic to your blog.

How do you draw this conclusion?

what I want to know is how does google know how many likes or twitter followers you have…

The information is public and something Google can see. However I’d be seriously surprised if Google was using follower counts as a leading indicator of utility… Actions per post are far more telling but even then one has to differentiate aggregate “likes” with the relevancy [and honesty] of who created them.

In another world Google+ would have been built on the backs of social networks to give Google insight to just that.