Thanks for the feedback. I have a Pinterest board here http://www.pinterest.com/IrongateGroup/office-supplies-web-store-open-to-all/
and have found that Twitter drives more traffic to my store. My blog is about to be re-launched too - and that was a great driver of traffic. None of this compares with e-marketing or Adwords... which I guess is fair enough. It costs nothing but a little time. Thing is I am selling a price sensitive commodity ... and the product isn't that fascinating :-) Social media will be more powerful with new developments we're working on in the b2c field though. Watch this space.