Promoting online business through article marketing/blogs?

[blackbird926]

I am currently trying to promote an online business primarily through writing eZine articles. I am aware that it is possible to do this on other blog websites such as Squidoo, Wordpress, etc. To this end, I have two main questions:

1) Does putting your article on multiple sites (e.g. eZine, Squidoo and Wordpress) increase the chances of it coming up in the Google Search engine?

2) Or is it better to just focus on writing in one website e.g. eZine and get a reputation for good articles through the one website in that way while retaining the maximum possible appearances in the search engine?

The main reason I'm doing this is to get maximum exposure to my website through blogs, so any advice would be appreciated.