Some very interesting stats from statcounter.com about the top social media platforms used in Australia.
Stumble Upon 15.65%
Seems there is a clear winner. ;-) Never the less I think there are different platforms for different purposes.
Another thing that is often forgotten is that using social media is not the magic key to success.
Facebook, Twitter and YouTube are just media channels. What counts to attract an audience at the end of the day is the quality of your content, your message and you campaigns.