What to use!

I often get a little confused when deciding what platform to build a social marketing campaign on. My first instinct is to use self hosted wordpress for a little bit of freedom but I could get the content indexed and ranked on search engines quickier by using Wordpress.com or Squidoo.

Then I was reading a post on Seth Godin’s blog  about exactly the same problem, do I need facebook, myspace, bebo etc if I have my own blog?