A few weeks into Google+, and most at least know of the new social networking site, even if they haven't joined yet. Still resisting? Based on its current growth rate, you may want to jump in sooner rather than later.
Below, I compare and contrast the network properties and social principles behind the most popular social platforms.
Facebook
Facebook's utility comes from helping users simply maintain all of the relationships in their lives. However, real-world relationships are complex. Not every relationship is the same, and every friend is unique. By collapsing all the different relationships into one bucket of "friends," Facebook created the problem of conflicting social spheres. Some groups just don't mix in real life, and some information is not for all friends—regardless of how close your relationship is.
Offline, people deal with that problem by spatial-temporal segregation. We simply meet different groups of people at different places and times. But on Facebook, we're stuck; we either don't share, or share with everyone. Although Facebook subsequently implemented features that allow users to place friends into groups, those features were Band-Aid fixes that didn't drive adoption. Google+ addresses that problem with Circles.
Friendship on Facebook is bidirectional, requiring both parties' consent to connect. Anyone can initiate the connection, but the other person must accept it to create a tie. Those mutual, reciprocal "friendships" help keep the relationships and content on Facebook relevant. As a result, the signal-to-noise ratio on Facebook is fairly high compared with other networks that require only unidirectional consent, such as Twitter.
However, bidirectional consent is not without cost. One of its drawbacks is that it requires the coordination and alignment of intent between two people. That is harder to achieve than it may seem and it limits a network's growth rate.
Twitter
Unlike Facebook, Twitter requires only unidirectional consent to connect with another user, resulting in greater growth potential. Despite Twitter's 140-character limit, it's grown at an astounding rate. Twitter use has spread so feverishly that Twitter has created a communication network with lower degrees of separation than the social networks in our physical world.
The average path length between any random pair of Facebook users is about 5.73, which is on par with the six degrees of separation in real-life social networks. But the average path length between random pairs of Twitter users is only 4.12. That means networks requiring only unidirectional consent could lead to a smaller world, where people are closer (i.e., the average path length is shorter). Accordingly, information spreads faster on Twitter.
The unique value that Twitter provides is the simplicity of the platform, which requires almost no effort to adopt and use; it's growth is directly attributable to that simplicity. That said, membership growth doesn't imply that users will continue to use the platform. In fact, the number of active members on the site is not very impressive at all. A significant number of Twitter accounts are inactive, and many active members are bots.
The biggest problem of a unidirectionally connected network is that it makes content less relevant. Twitter streams ("timelines") are often flooded with noise; tweets have a low signal-to-noise ratio. Twitter implemented lists, a receiver curation mechanism, to help users curate content—but lists are insufficient. Like any unidirectionally connected network, Twitter connections are much weaker. The ties that bind Twitter users are less cohesive, more fragile, and therefore less sticky—a probable contributor to Twitter's low ratio of active-to-total user base.
Google+
Like Twitter, Google+ requires only unidirectional consent to connect. Though that approach aims to combat some of Facebook's more complicated alignment of relationships, the resulting growth also makes the network noisier. To deal with the noise, Google+ has Circles that enable receiver curation.
But will Google+ turn into a glorified Twitter? If people fail to put their connections into the proper circles, then Google+ can certainly turn into just another noisy stream. However, even if people spend time to categorize their connections, there's still no guarantee that receiver curation is a strong enough filtering mechanism to deal with the noise.
Google handles both of those problems very well with its user-experience design. To encourage the use of Circles, Google+ "gamified" its Circle Editor. Categorizing connections is both simple and fun.
To deal with the problem of receiver curation, the Circles feature enables an additional mechanism: sender curation. Users can selectively share with different subsets of their connections using a combination of individual users, circles, extended circles, or the public. Though sender curation isn't unique to Google+ (Facebook and LinkedIn automatically incorporate those mechanisms due to the bidirectional nature of those networks), its effectiveness depends on the sharing behavior of the sender.
Aside from its social network, Google+ also provides many community-building tools. Google+ has made it easy for people to find content they are passionate about via Spark. And if there is ever a need for high-bandwidth, face-to-face communication, users can start a Hangout (video group chat) with up to 10 people.
Those tools enable relevant groups of users to hold conversations about a common interest, which can eventually develop into real relationships. So Google+ is not only a social network but is also overlay with communities, which is how humans operate in the physical world.
And the Winner is...
Now, is Google+ the ultimate answer for managing our relationships? Probably not. In real life, our relationships are very complex. Each is unique. In Google+, everyone would be his or her own circle, nested inside a complex hierarchy of context that changes over time. As for features, Google+ definitely packaged a lot of essential social features in a well-integrated platform, so +1, Google+.
For Google+ to win, it needs to gain users with lots of friends who can bring those friends to the new platform. However, Facebook is still more than 70 times larger than Google+. Its true strength, however, is not the sheer volume of its user base but the cohesiveness of its networks.
Facebook contains many strong ties: families, close friends, high school buddies, etc. Having a lot of those strong connections is what makes Facebook extremely sticky. Strictly from a network value perspective, the more friends a person has on Facebook, the more utility she can derive from the network (i.e., network effect).
Conversely, more is lost by switching to Google+, where connections may not be present. That's why users with many friends (and who can bring many friends to Google+) are precisely those who are hardest to get—because they are least likely to switch. Users who have few or no friends are the easiest to switch, yet they are least effective for driving adoption of the new network.
For a more complete picture, consider the business ecosystem built into these platforms. Facebook has been around for eight years and has a large network of partners and developers who have built apps and businesses on the Facebook platform. Some of those partners (e.g., Zynga) even spawned entire industries.
Likewise, Twitter (five years old) strategically opened a sampling of its data via its public API. That resulted in a huge ecosystem of software apps, tools, services, and businesses. Those business relationships are not going to disappear overnight. And Google+, only a little more than few weeks old, clearly doesn't have that external infrastructure yet.
So who is going to win? I foresee a fragmented social networking marketplace without a single dominant player. Google+, Facebook, and Twitter have their own unique strengths and niches. The only clear winners, in the end, are consumers. A healthy amount of competition drives innovation, differentiation, and specialization. As the industry matures, convergence and interoperability will ultimately lead to better service for the end users.
