What is this gclid?

Posted by Planet Malaysia on November 11, 2007

While checking on our sitemeter referral link lately, we found a funny URL:

http://www.planetmy.com/?gclid=CJyDgIrL0o8CFR0oTAodTR6FCg

What the heck is this? We don't have such URL. We don't have such destination link.

My best friend 'Google' tell me the answers and details.

What is Destination URL Auto-tagging?

In order for Analytics to display details about your AdWords keywords and costs, you must do one of the following:

Use Destination URL auto-tagging, or
Manually tag your keyword destination URLs with tracking variables.

Google created auto-tagging (turned "on" by default) so that large and small accounts could easily see how their AdWords keywords were performing from click to conversion and back to cost. Auto-tagging automatically associates a parameter with the click on your ad which then allows Analytics to report the details of the click, including which AdWords keywords brought a visitor to your site, which campaign that keyword was from, and how much that click cost. This information can then be associated with richer information within your Analytics reports, such as goal or e-commerce conversions, to give you a sense of how your AdWords spending is really performing.

The parameter used in auto-tagging is called "gclid" and will show up in your landing page URL when a user arrives at your site from your ad. For example, if your site is www.mysite.com, when a user clicks on your ad it will appear in the address bar as:

www.mysite.com/?gclid=123xyz

Note: A small percentage of websites do not allow arbitrary URL parameters and serve an error page when auto-tagging is turned on. Please consult with your webmaster to find out if this is the case or turn on auto-tagging and do a test by simply clicking on your ad. If the link to your site works then you can use auto-tagging. If you are getting an error, you'll need to turn auto-tagging off from your AdWords account (see steps below). Then, ask your webmaster to allow arbitrary URL parameters before turning it back on.

To disable auto-tagging: