How to advertise with blogger, wordpress, myspace?

Hello, I created a website and I was wondering how could I use blogger, wordpress, myspace and the like to advertise my business without being a spammer. At first I thought I could use copies of the content so that a lot of people see my content, but then I read that Google penalizes duplicated content.

So, do you guys know of any way to do this?
I hate spammers, I don't want to become one, I just want to use those services to gain a little more traffic.

Thank you for your help

 

Change up the content a little for the blogs. Like change the introduction, conclusion, etc.

 

audbot, thanks for answering, I'll look into that.
Also, I would like my blogs to be a complement to the main site, like an "added value".

Anyone here uses blogs as complements to their main site?
I'd like some ideas as to how I could offer an added value.

Thanks!!