Social networks seemed poised to take over the Web. This year, Facebook reached 800 million users. LinkedIn went public in a blockbuster stock offering. Twitter produced a billion tweets per week. And Google launched its own social network, Google+, attracting 25 million users in one month.

Amid the continued growth of these social networks, there has been much excitement about how the rest of the Web would soon be infused with all things "social": social search, social commerce, social deals and more. And yet the effort to socialize the rest of the Web has so far failed to live up to its promise. Why?

How Will Social Networks Evolve? What Services Will They Deliver?

David Rogers is consultant, speaker, and author of "The Network Is Your Customer." He teaches at Columbia Business School and has advised numerous companies such as SAP, Eli Lilly, and Visa. This article originally ran on The Network, Cisco's Technology News Site. The contents or opinions in this feature are independent and do not necessarily represent the views of Cisco.

Facebook's master plan, articulated by founder Mark Zuckerberg, was that once its site had built a map of everyone you've met or known, you would be able to leverage that information across the Web, to see what your "friends" are searching, buying, watching, liking or saying.

Since 2008, Facebook has attempted to roll out this strategy by using "Facebook Connect" to extend its social graph into millions of other websites, and by incorporating new functionality into its own site. Yet many of the most anticipated social integrations so far have failed to take off:

  • Social commerce: When Delta Airlines launched a Facebook "ticket window" last year, it was seen as the future of e-commerce, with every ticket purchase shared socially to the customer's friends. Yet, one year later, nearly all of us still buy our tickets on dedicated airline or travel sites.
  • Social search: When the Bing search engine started highlighting Web pages that the user's Facebook friends "liked," it heralded the arrival of a long-awaited "social search." Yet, the fraction of "liked" pages was so tiny that the social feature was nearly invisible.
  • Social deals: When Facebook moved into the daily deals space, it was seen as a potent challenger to Groupon. But four months later, Facebook announced it was closing its local deals business.
  • Social viewing: When Facebook offered its first streaming movie this spring, on a Time Warner Facebook app, it was heralded as an opportunity to make movie viewing social. Yet, this experiment failed to produce much customer interest.

At last week's F8 conference, Facebook unveiled much more ambitious efforts to integrate outside web brands into its site - from a full-fledged Netflix movie player, to a music player drawing on Spotify and several other streaming music services.

But for any of these, or other social integrations to succeed, Facebook and its partners and rivals will need to learn from past mistakes. To date, their vision of how to make the Web more social has been based on a fundamental misunderstanding of our digital behavior.

But for any of these, or other social integrations to succeed, Facebook and its partners and rivals will need to learn from past mistakes. To date, their vision of how to make the Web more social has been based on a fundamental misunderstanding of our digital behavior.

Understanding Social Graphs vs. Interest Graphs

In order for social networks to truly reshape our experience of the rest of the Web, developers must first understand the relationship between our social graphs and our interest graphs.

A social graph is a digital map that says, "This is who I know." It may reflect people who the user knows in various ways: as family members, work colleagues, peers met at a conference, high school classmates, fellow cycling club members, friend of a friend, etc. Social graphs are mostly created on social networking sites like Facebook and LinkedIn, where users send reciprocal invites to those they know, in order to map out and maintain their social ties.

An interest graph is a digital map that says, "This is what I like." As Twitter's CEO has remarked, if you see that I follow the San Francisco Giants on Twitter, that doesn't tell you if I know the team's players, but it does tell you a lot about my interest in baseball. Interest graphs are generated by the feeds customers follow (e.g. on Twitter), products they buy (e.g. on Amazon), ratings they create (e.g. on Netflix), searches they run (e.g. on Google), or questions they answer about their tastes (e.g. on services like Hunch).

Photo by duchesssa

Next page: The Fallacy of Social Web 1.0

The Fallacy of Social Web 1.0

The fundamental stumbling block of the social Web to date is that it has conflated social graphs with interest graphs. But in reality, who you know does not always translate into what you will like.

For example, I have a particular taste in movies. But I do not share that same taste with most of the people whom I have friended on Facebook - a motley mix of high school classmates, work colleagues, PTA committee members, and fellow jazz buffs. Nor do we, as a large and heterogeneous group, all share the same taste in travel, or fashion, or much of anything else. So when Facebook attempts to improve my movie-viewing experience by revealing the tastes of everyone in my entire social graph, the value to me is quite low.

The fundamental stumbling block of the social Web to date is that it has conflated social graphs with interest graphs. But in reality, who you know does not always translate into what you will like.

The Future of the Social Web: Integrating the Graphs

So far, the job of mapping users' social graphs has been taken up by social networking sites like Facebook and LinkedIn. Meanwhile, interest graphs have been best built by e-commerce sites such as Netflix and Amazon that focus on highly customized recommendations.

The future of a truly social Web will rely on getting these two types of graphs to work together. We are just starting to see some interesting attempts at this:

  • Social circles: On Google+, users explicitly place each member of their social graph into one or more "circles" based on common interests and the type of content they want to share with them. In response, Facebook has just re-launched its own feature to manage social circles.
  • Feed lists: Twitter's lists feature allows users to create sublists of people and brands to follow based on different topics (e.g. news headlines, favorite celebrities, fellow sports fanatics, or authors you admire).
  • Single-purpose graphs: Niche services aim to map out just one particular circle of shared interest, such as micro-social-network Path (for mapping your 50 closest friends), or social music site Turntable.fm (for sharing playlists with likeminded music lovers).

In the near future, we should see new and better solutions to integrating social and interest graphs.

For Now, Pick the Right Graph

Until this kind of integration is achieved, though, Web services should consider carefully when to utilize the customer's social graph, and when to use their interest graph.

Then the service should pick the graph that adds value to the customer experience. Because the real social Web will be all about the customer.