So the key would be to override the query parameters in the _trackPageView call directly, e.g. _trackPageView('/?utm_source=…'), rather than setting the codes on the page URL. Have you tried this technique yourself?

I probably got started down this path the same way most people do. I noticed my campaign links showing up in Google search results and I panicked. I didn’t realize that it takes time for the Google crawler to process the canonical header link and update their index. In my case it took about 3-4 days.

My first approach to solving this was exactly as you suggested. I clicked the checkbox labeled ‘Use # instead of ? for Campaign tracking?‘ in your Google Analytics for WordPress plugin. Then I started adjusting all my existing redirects to use the ‘#’ rather than ‘?’. When I changed my Apache mod_rewrite rules I found that Apache escaped the ‘#’ and turned it into a %23. I thought I might run into similar problems with other websites not accepting campaign tracking with ‘#’, so I figured campaign tracking with ‘#’ wouldn’t work for me. (Note: I know better now – for anyone else looking for the answer to this, use the noescape option in the RewriteRule to prevent Apache from turning it into a %23).

Another motivation for not using the ‘#’ hash fragment for the campaign tracking was due to a photography website that I’m currently putting together. The photography website uses an AJAX interface to allow switching between images quickly without doing a complete page reload (similar to what is done on smugmug.com). To keep a proper history state in the client’s browser, this site stores its photoID (identifies a specific/unique photo in a gallery) in the ‘#’ fragment. This modifies the URL so the browser’s ‘Back’ and ‘Forward’ buttons work correctly – and, since it only modifies the ‘#’ fragment, it doesn’t trigger a complete reload of the web page. It is also used so that the client can add a bookmark while looking at a specific image and, when they visit that bookmark, the site will fetch that same image.

That’s probably a longer description than needed, but using the ‘#’ fragment for campaign tracking on this photo site would interfere with the AJAX navigation that is also done using the ‘#’ fragment. I was looking for a solution that would keep search engines from seeing (and indexing) the campaign variables while at the same time not interfering with the ‘#’ based navigation features of the photo site. And that is how I arrived at this solution.