URL Formatting for Internal Link Tagging

[RobbieFoglia]

After doing some research on internal campaign link tagging, I have seen conflicting viewpoints from analytics and SEO professionals regarding the most effective and SEO-friendly way to tag internal links for a large ecommerce site.

It seems there are several common methods of tagging internal links, which can alter how Google interprets these links and indexes the URLs these links point to.

1. Query Parameter - Using ? or & to separate a parameter like cid that will be appended to all internal-pointing links. Since Google will crawl and index these, I believe this method has the potential of causing duplicate content.
2. Hash - Using # to separate a parameter like cid that will be appended to all internal-pointing links.
3. Javascript - Using an onclick event to pass tracking data to your analytics platform
4. Not Tagging Internal Links - While this method will provide the cleanest possible internal link paths for Google and users navigating the site and prevent duplicate content issues, analytics will be less effective.

For those of you that manage SEO or analytics for large (1 million+ visits per month) ecommerce sites, what method do you employ and why?

Edit* - For this discussion, I am only concerned with tagging links within the site that point to other pages within the same site - not links that come from outside the site or lead offsite.

Thank you

[RobbieFoglia]

Thanks for the answer. I will be using Ensighten to manage the link tagging, so any of the options I presented can be utilized.

Have you found any negative consequences associated with using the query parameter to tag internal links, such as duplicate pages indexed? Or does the Webmaster Tools setup and canonical tags eliminate the chance for this happening?

The query parameter is also used in the URL outside of tagging (for sorting, brand, and other refiners). Is it possible to specify that you want certain query parameter-appended URLs crawled and not others?

[Ray-pp]

I manage a large traffic ecommerce website and use Google Tag Manager to tag all internal links for review in GA.

If you want to use a query parameter, which I also actively use, you can apply settings in Google Webmaster Tools to ignore them and not cause duplicate content issues.