For the purposes of this post "Social Networks" translates to "Publishers." My company, Gnip, brings the public, real-time, activities created by users on Social Networks to our customers. From a vocabulary standpoint, we simplify things and refer to these Social Networks as Publishers.
Over the past four years Gnip has seen a lot of Publishers come and go. Not surprisingly, a pattern has emerged around how they evolve, and the degree to which our customers need their data. There are generally three distinct phases a Publisher goes through, and how they do in each phase impacts how they ultimately participate in the broader social data ecosystem.
Participation in the social data ecosystem can yield a full commercial cycle for the Publisher. This cycle being one combining consumer use (expressing buying intent, or ranting about a product) with commercial engagement (ad buying or addressing a problem with your product).
Phase 1: Consumer Engagement
A Publisher must engage consumers. Whether via a homegrown social graph, or leveraging someone elses (e.g. Facebook Connect), in order for a Social Network to become useful, it needs users. From there, those users need to participate in self-expression (from posting a comment, to re-tweeting a tweet) and generate activity (aka "Publish") on the service. There are a variety of ways to compel users to engage in a social service, but the Publisher itself is responsible for the first experience. The vision of the services' founders yields a web-app or mobile interface that allows us to take action, leveraging the expressions laid out by the app itself (e.g. sharing a photo). If users like the expressions, discovery methods, and sense of "connectedness," you've got a relevant Publisher on your hands.
Phase 2: APIs; Outsourcing Engagement
At some point a successful Publisher realizes the potential for outsourcing the expression metaphors that make the service successful & useful, and they construct an API that allows others to RESTfully engage with the service. In some instances the API is read-only. In some instances the API is write-only; sometimes it's both. What is key is that nine times out of ten, the API is meant to drive core service engagement via other user-facing applications. A classic example of this would the zillions of non-Twitter Inc clients that "tweet" on our behalves everyday. One look at the endless number of tweet "sources" that flow through the Firehose and you'll realize this engagement potential; there are tens of thousands of client apps.
The exceptional API is one that has broader social data engagement ecosystem consumption in its DNA. Typical Publishers consider themselves the center of the universe, and that not only will they capture all consumer engagement, they will be the root of all broader ecosystem engagement as well. However, success with consumer engagement does not guarantee commercial engagement; not by a long-shot. This center-of-the-Universe perspective is highly limiting for everyone involved. A great example of this is simply how you see Facebook and Twitter logos in cafes. The retail outlet couldn't care less about which Publisher du jour is hip. All they care about is reach, and they'll promote any social service they think yields reach; they have zero affinity to your social service.
Some services execute phase 1 and 2 simultaneously these days.
Phase 3: Activity Transparency; Commercial Engagement
Allowing other applications & developers to inject activities into the core service is obviously valuable, however it is only part of the picture. Publishers with broad social and commercial impact have achieved this success by addressing commercial needs for complete, raw, activity availability. For example, in order for someone to effectively deploy resources in a disaster relief scenario, they need to make their own determination as to what victims need, where they are located, and general conditions surrounding the event. The Publisher limiting access to the public activities taking place on the service, by definition, yields an incomplete picture to downstream commercial consumers of the content. The result is a fragmented & hobbled experience for commerce engagement.
The most impactful, useful, and valuable Publishers that Gnip customers leverage for their needs (ad buying, campaign running, stock trading, dissaster releif), are those that acknowledge that they are not an island in the ecosystem. They complete the cycle by providing unfettered access to one of their most significant assets; the public real-time firehose of all the activity taking place on their service. In trade, the relevance of the Publisher itself is maximized because commerce can engage with it. Whether the ecosystem has to pay for that access is a separate topic. The availability of it at all is the finer point.
A good example of how impactful this transparency can be is Twitter. Consider how Twitter is used across new, as well as traditional, media. They've completed the commercial data ecosystem cycle with a strong offering in Phase 3.
All three phases are not required for success, but all three are indeed required for success in the broader social data ecosystem.