New to SEOmoz, loving it so far.

I promote content on my site a lot and am diligent about using UTM tags to track conversions & attribute data properly.

I was reading earlier about the use of link rel=canonical in the case of duplicate page content and can't find a conclusive answer whether or not I need to add the canonical tag to these pages.

Do I need the canonical tag in this case? If so, can the canonical tag live in the HEAD section of the original / base page itself as well as any other URLs that call that content (that have UTM tags, etc)?

Thank you.