For a long time talking about how social media influence the results in search engines. Every day in social networks are sharing millions of links. Leaders in the search - Google and Bing - detect "signals" which users of these media send. And use the signals in their algorithms.
Let's see, which are those factors that influence the results?
For Google, retweets are an important factor in determining rank in the organic results and news results.
Important for Bing is the prestige of the user, which retweets. Retweets are most important for the results in "Bing Social Search".
The authority of users is important for both engines, but they take advantage from the signals by different ways.
Google does not identify users personally, but defines their "prestige" in a special way.
Bing connects famous people with their accounts. ( So you must become famous:) ).
Weighting of links
This signal is important for Google when people search in real time. The authoritative links do not influence the results of other services.
The popularity of the account is important for Bing. The system tracks who publish links. ( Again, I say - become famous!!! )
Google monitor links from Facebook, as it does on Twitter.
Bing select only links that are shared by all. It Furthermore, captures links from Facebook pages.
The algorithms of Google calculate the "importance" of Facebook users, but did not identify them.
Bing does not include this signal in their algorithms, and it does not affect the search results.
Weighting of links
Google analyses your Facebook reputation, because it is all-important for the weight of your links.
For Bing, the links are significant when they are be shared in large quantities at Twitter and Facebook simultaneously. This is a signal that the links are important for many people. And it increases their weight.
Here it is a video from Matt Cutts, Google’s Webspam team.
In conclusion I would say ....