I found a Harvard Business Review blog post that really zeroes in on some of the productivity gains and huge potential for organizations that leverage their social platforms correctly.
Good stuff in general, and the McKinsey Global Institute research could be helpful in supporting your ongoing business case.
Some key excerpts, in my opinion:
Social technologies — the software and services that make it possible to show off your vacation pictures to all your Facebook friends and follow your favorite team tweet by tweet — are not just giant time sinks that keep your employees from getting their work done. On the contrary, they may become the most powerful tools yet developed to raise the productivity of high-skill knowledge workers — the kind of workers who help drive innovation and growth, and who are going to be in increasingly short supply.
the potential for value creation when social technologies are used to improve collaboration and communication within and across enterprises is twice as big as the value that can be created through all other uses across the value chain.
Even better, on social platforms, communications become content — forming a searchable archive that can be continually enriched with comments and additions by members of the online community. So, when the expert in the group answers the question about how to account for depreciation in Turkey, everybody can see it or find it later.
Participation, in turn, depends on having an environment of openness, information sharing, and trust — the sort of culture that many organizations have not yet established. For this to happen, leaders must take the lead — after all, these are social technologies. Leaders will have to role model the use of these technologies, explain how to use them to drive value, observe success stories and help them to scale up to the rest of the enterprise. At the same time, these technologies are only as effective as the degree to which individuals participate, so lessons from consumer social applications can be applied in the enterprise.