When you're talking to people within your organization to start gauging interest or need for a social collaboration solution, the best approach is to be very conversational.
When the word "social" is a barrier in your corporate culture, a good way to start a conversation is to ask leaders (or members) of a team about how they work together today. Example responses will likely be:
Conference calls (Phone or video conference)
Sitting together at desks
What tools do you use to get your work done?
Next, ask these questions:
How much of your work week do you estimate you spend in meetings?
How much of your work week do you estimate you spend doing email?
How many hours or days does it typically take to find someone across the company who can help you?
The above points will very often lead to conversation around pain points such as:
How do you make decisions as a team? (We don't have a real process / In email / verbally)
How do you document those decisions? (It depends / in email / in meeting notes that are stored on a drive)
When someone leaves your team, how do you access their past contributions to the team? (By memory / searching emails / calling them at their new job)
How do you find expertise in the company outside of your team or immediate area?
(I ask my boss or coworker if they know of anyone)
How do you find information that will help you get your job done quickly?(I spend a lot of time in email - searching, sending)
How do you currently co-author and track document changes, and are there challenges with that?
(On individual desktops / email / manual merging)
Once you're having an engaging dialog that is personal to all involved, it's easier to ask those folks if their team would benefit from a central system of collaboration, which will enable them to:
contribute from wherever they are
find information and expertise faster
capture important historical context around project work, product development, etc
document actions and decisions in a way that's easy to look back at later