One of the first things we recommend when it comes to getting into social media marketing and creating an effective strategy, is to really understand your goals and which social sites are most likely to help you accomplish those goals.
Some companies are looking for lead generation, others want more visibility around their content, while some really just want their brand to be visible in the top social media sites.
Regardless of their goal, user demographics always play a role in how successful your content will be and should be consider when creating your strategy.
The data is from 2012, but it still gives you a pretty good glimpse at the demographics for social media users in general, which can help you when creating a good strategy or implementing an existing marketing campaign.
I found it interesting that even back in 2012, more adults where on LinkedIn than on Twitter, which as we have seen a huge growth in LinkedIn, is likely to be even higher today.