Bing and Facebook announced an extension to their existing agreement today.

From the Bing Community blog:

Today we announced an exciting expansion to our long-term partnership with Facebook.  Specifically, we are rolling out some new features that allow you to take your friends with you into your Bing experience, both at www.bing.com as well as within the search experience at www.facebook.com. We will enable a great search experience for people queries, by bringing in information from your Facebook friends and people who share networks with you, and we will show you what your friends have liked (using Facebook’s public like platform) as you navigate through search results in Bing.

Why is this interesting?  At the customer experience level, search is getting more social and more personalized.  We think that’s a great thing to help you make better, more informed decisions.

But we think there is something more profound going on under the covers, an inflection point in the search industry that will enable more interesting social scenarios in the future.

Traditionally, search engines rely on a large number of clues to help us determine what you are looking for.  We call these clues “signals.” Search was built on a concept of these signals that told engines what was probabilistically the most likely piece of information you wanted based on the words you entered.

This has worked pretty well over the years and helped search improve a lot – early signals like meta tags to give the engines hints on page content and reverse IP to provide more locally relevant results, which has evolved to the mobile phone with the addition of geo-location data.  Eventually the industry developed more complex signals like anchor text and popularity models to try and bring a human element into the mix.  In Bing, we look at more than 1000 signals to try and get you the best result.

Our focus at Bing on helping customers make better decisions allowed us to rethink this model a bit, as we believe in some ways the current set of signals is not perfect for the way people actually make decisions and accomplish complex tasks.

The fact is the real world isn’t defined purely by how information is connected; it’s also defined by the connections between people.

While the Bing argument for social search sounds logical in theory, I think they will find adoption rates of their social search experiment – illogical.