what is social media?

i'm sure there are many many definitions about social media, so i shan't add to the already saturated or diluted (depends on how you look at it) pot of ideas, but if i may, i'd just like to propose in a nutshell as to what social media means to me:

when you and i produce content that is accessible to someone else, that content is social media

why is this important? it means we have the power to publish, and become something like citizen media, and hence 'social' media. available to your fellow man via the internet, wifi, wimax, mobile device.. etc only problem is, we tend to be rather unregulated, and the number of illegal porn sites should bear testament as to how deep the south is where we're standing.