Social media does not lend itself to a one-size-fits-all approach.
For example, if your target audience is in the 18-24 age range, Google+, Reddit and StumbleUpon has more consumers that age than Facebook, Twitter and LinkedIn (according to the Social Barrel data below).
If you want to drive traffic to your website, focus your efforts on Facebook, Twitter, Pinterest, StumbleUpon, Reddit and SlideShare.
The infographic below, created by Social Barrel, helps brands tailor their content creation efforts to match different social media platforms, depending on what they want to achieve:
(Infographic via Social Barrel)