Google did respond in time and launched its social media platform Google+. Since Google is king in search it smartly integrated Google +1 with Google search relevance hoping that it will force people to adapt to using Google+ over Facebook.
Google modestly achieved their target but Facebook is still number 1. When Mark Zuckerberg and Bill Gates realized that there is a very great potential in becoming partners they were quick enough and Facebook exposed itself for better crawling with Facebook pages and profile.
Today you can actually use Bing to really do smart queries on Facebook. I will cover that at a later stage. So the crux of the matter is Bing shows Facebook results better in web search. Well one very basic example is Latest Tech tips Facebook fanpage.
Here is the Google search result for “Latest Tech Tips”. Google naturally focuses on +1s on Google+ even for a Facebook Fan page result. However it makes the search result less intuitive.
Since bing has collaboration with Facebook it shows a more natural search results. Bing even goes upto the extent of showing total Facebook likes as well as number of people talking about the fan page. This makes the result more natural.
Even though both search results look extremely similar their Social media priorities are clearly evident and webmasters also must consider the Social Media SEO in mind and give some effort for Bing optimization.