If, somehow, you failed to take part in the Econsultancy and bigmouthmedia Social Media Survey you don't get it for free. You can download it here for less than £200. It's probably the most important social media business benchmark in the UK to date.
If you're not an Econsultancy member or can't talk your bean counters into splashing the cash needed for the insight - then you can check out bigmouthmedia's Really Useful Guide to Social Media. To be honest; if you're reading this blog then you're not likely to be in the intended audience for the guide but it does contain a small sample of the survey stats!
The Really Useful Guide to Social Media