Most people know Facebook as a social network, not a technology company. Well, data released by Facebook today shows that Facebook users are searching in large volume: 500 million Facebook searches were conducted in May alone. During the same time period, Google handled about 3.85 billion searches. I think it’s interesting that Facebook is processing a meaningful number of searches when compared to the total number of times Google is used nationwide (about 13% of Google’s volume, in fact) .
Obviously, the technical challenges at Facebook are quite different than those outside the context of a social graph (Wink and ZoomInfo are two startups attacking the more general people search problem). Instead of indexing and organizing the whole web, Facebook indexes only the information created by its users and sorts by social graph distance, so the same search returns different results for every user:
Facebook search results are sorted by an approximation of social graph distance. People closer to you in the graph—your friends and people in your networks—are likely to be more relevant to you and thus are ranked higher. We also use this concept of “social proximity” to order results within applications like groups and events. Facebook search’s key differentiator is that search results are unique to every user because they are based on a individual’s place in the social graph.
Facebook lets you search its entire database of users and see names and networks of people in your search results, regardless of your degree of connection to them. By contrast, LinkedIn only shows names of search results within your 3rd-degree network and 20 out-of-network search results (though you have to pay to contact them) (you can also purchase access to more out-of-network search results). However, LinkedIn does allow you to access the profile pages of people in your search results, whereas most Facebook users usually require a 1st-degree connection or being in the same network.
Based on an off-the-cuff estimate, I estimate that about 80% of the people searches I conduct are searches for people within my geographical area (San Francisco/Silicon Valley, CA) or third-degree network. For these searches, Facebook and LinkedIn are able to provide much more relevant results for me because they can take social proximity into account when ranking results. While search engines that crawl the web can provide a basic level of white pages functionality, they can’t provide that same value. As Facebook continues to grow in popularity, I wouldn’t be surprised to see it build on its lead as the most popular people search engine on the web.