Querystring params, rel canonical and SEO

[NicB1]

I know ideally you should have as clean as possible url structures for optimal SEO.

Our current site contains clean urls with very minimal use of query string params.  There is a strong push, for business purposes to include click tracking on our site which will append a query string param to a large percentage of our internal links.

Currently:

http://www.oursite.com/section/content/

Will change to:

http://www.oursite.com/section/content/?tg=zzzzwww

We currently use rel canonical on all pages to properly define the true url in order to remove any possible duplicate content issues.

Given we are already using rel canonical, if we implement the query string click tracking, will this negatively impact our SEO?  If so, by how much?  Could we run into duplicate content issues?

We get crawled by Google a lot (very big site) and very large percent of our traffic is from Google, but there is a strong business need for this information so trying to weigh pros/cons.

[RobertFisher]

NicB1

The myth is that clean urls are better for indexing, etc. Actually, you do not need to change dynamic to static unless you are worried that the CTR may diminish a bit due to not having a clean url. Personally, I don't think today that even happens more than rarely.

So, go forth and analyze. Now on the off chance there are some who would think that my having started drinking when I got up this morning was effecting my judgement, I went and pulled an old Google WMT post:

http://googlewebmastercentral.blogspot.com/2008/09/dynamic-urls-vs-static-urls.html

Best

[NicB1]

Overall I think we are OK, but I just want to point out that since we'll be adding click tracking, we could have numerous urls that all resolve the same page.  The "tg" element in my example will change just due to what specific link a user chose to select (but the content of the page will be exactly the same).

One page
http://www.oursite.com/section/content/

Internal links to that page

http://www.oursite.com/section/content/?tg=zzzzjj6

http://www.oursite.com/section/content/?tg=zzzzww2

http://www.oursite.com/section/content/?tg=zzzzyy1

http://www.oursite.com/section/content/?tg=zzzzvv4

The tg is irrelevant as an identifier for the page.  I don't think that is a problem but it is a slightly different use case as outlined in the referenced Google article.