Tracking user conversions

Hello,

I run an e-commerce site that is implementing a blog using WP. I’d like to be able to run some metrics off of this, but the most basic one is how can I track conversions of people that came from the blog?

I’m already using Google analytics for my site, and I’ve setup the Google Analyticer plugin for the blog (which is on the same domain in a sub-directory). What I was thinking is being able to is add under additional tracking code the following:

utm_source=”blog”;

Thinking that this will set a “campaign” that this user is tracked against in Google Analytics. Will this work, do you have any better recommendations? Thanks.