I noticed in the past two or so months, after Google upgraded their SERPs to enable users to rearrange and delete results (see thumbnail to right) that the outbound links Google was posting on SERPs were redirects through the google.com site (meaning, they were tracking clicks on outbound links.)
Since I often search for something on Google, then “right-click”, “Copy” to get a link, I noted the links were not the actual links, but Google.com links. This went away shortly thereafter.
For example, one of our decent organic result page for the search “ROI Tracking” shows us as:
<a class="l" onmousedown="return clk(this.href,'','','res','4','')" href="http://www.conversionruler.com/">Measure and manage your PPC Marketing Campaign Performance with<b>...</b></a>
For this post, I’m going to focus on the technical breakdown of what “clk” is tracking.
clk generates an image-bug tracking call. The parameters to clk are:
- 1st parameter: The URL you will be sent to (this.href)
- 2nd parameter: Original Intention (Guess?) (”)
- 3rd parameter: Referring domain (from toolbar) or affiliate (Guess?) (”)
- 4th parameter: Where you clicked (res for Search Results, clnk for Cached links)
- 5th parameter: The position of the result you clicked on (1, 2, 3, 4, etc.)
- 6th parameter: “Extra” parameters to pass (probably for future compatibility or labs) (”)
What Google is tracking
Google tracks your link with a query string to:
http://<google domain>/url?sa=T&source=web&oi=(Parameter 2)&cad=(Parameter 3)&ct=(Where you clicked)&cd=(Search Position)&url=(URL to be sent to)&ei=(Security Code)
Here’s the breakdown:
|url||The url you are clicking on||http://www.conversionruler.com/|
The tracking function on the Google site to invoke.
X appears for spelling corrections
|source||Where the search originated from.||web|
The original intention of the search?
|spell when the user misspells a word and corrects it with “Did you mean …”
coopctx found in log files.
revisions_inline when the user clicks “Searches Related to” on the SERP page
Appears to be a referrer, affiliate, or client token.
|So far only seen with google maps, it is a number (6,7,8, etc.) which I’ll assume are Google internal map application identifiers.
It appears to be the search origination, when it begins with a letter, it’s a site:
cad=Tvtrip.com (extensive client of Google maps)
I have a feeling that when Google Toolbar automatically extracts an address from a web page and forward it to maps.google.com, this is the original domain.
|ct||The click location.||res for results
clnk for Cached links in results
other codes TBD
|ei||Security code, encoded user identification, timestamp, or some combination of all three.||This value is identical for all results on a page, but appears to change page to page.|
|cd||Search result position||1,2,3,4, etc.|
The parameters here apply for many of Google’s Referring URLs as well, so feel free to use these definitions as you see fit.
If you find this useful, please link or comment. If you have further information, I’d appreciate it if you’d share in via inbound links or comments.