A recent post on the Google Analytics blog helps to explain some of the issues surrounding the auto-tagging of a Google AdWords account so that the data is automatically recorded and displayed within Analytics, if both options are being used. Because the auto-tagging creates a dynamic parameter that's attached to the link URL from the AdWords advert, this can sometimes create issues for websites.

The blog clearly explains how the tagging parameter works and ways that this can be tested before implementing the link, depending on the URL structure of a website. It also reminds users of possible issues if redirects are used through third-party tracking systems, or sometimes servers may block or remove the gclid parameter that AdWords adds to the PPC advert links. In some cases, problems with auto-tagging mean that AdWords links need to be manually created and the blog post finishes with guidelines on doing this.