I think part of the answer to this question depends on your definitions:
"social media" (to me, and maybe this is only because I'm old and have been doing this A Long Time) = forums, discussion boards, wikis, Facebook, twitter, instagram ... etc. If you have a login (you are a person) and you can share content in response to other people's content, it's social media
What is not social media are traditional websites, with no commenting or user-generated content.
If you look at the issue through that lens, then I think it becomes a series of questions:
* where do people go to find out background info (about your issue, your cause, how to use your thing)?
* where do people go to get "official" info (news, updates) -- where do they see the info, then where are they sent for the longer version of the info?
* where do people go to get help, ask questions, find others like them?
That (to me) leads you to a construct where you have:
* a website (with info about background - what it is, who you are, why you exist)
* news output (to twitter, FB, G+ -- Whereever your audience is anyway)
* discussions that happen in whatever medium your audience is most comfortable with (whether that's email or a forum or FB). It's also good practice to ''surface" the most relevant/helpful useful of those discussions back to both the "news output" and the website
My $.02, YMMV.