Central Perk: What is “?gclid=” & Why is The Analytics Cookie (Not Set)?

vineri, 13 iulie 2012

What is “?gclid=” & Why is The Analytics Cookie (Not Set)?

Posted: 12 Jul 2012 04:51 AM PDT

Recently we were a little stumped with gclid and the Google Analytics cookie that's placed on user's computers. We were asked:

"I went to my website through an ad, and the Analytics cookie set on my computer says: utmgclid=StrangeGibberishHere456|utmccn=(not%20set)|utmcmd=(not%20set) )|utmctr=my%20search%20term – why are the medium and campaign not set?"

So we did a little digging around to figure out why 'utmccn' was 'not set' and thought it was appropriate that we share it with all of you too. So here's the low down on what we've learnt:

When an AdWords account is linked to an Analytics account, and you enable automatic tagging, AdWords uses the gclid to hide all the information it needs to pass to Analytics.

If the link between Analytics and AdWords is set up properly, you shouldn't see "?gclid=" in Analytics – it should recognise the tag as being from AdWords and decode all the data from it.

See the Analytics Help page on auto-tagging.

Going back to the initial query:

"I went to my website through an ad, and the Analytics cookie set on my computer says utmgclid=StrangeGibberishHere456|utmccn=(not%20set)|utmcmd=(not%20set) )|utmctr=my%20search%20term – why are the medium and campaign not set?"

The medium and campaign are set – it's just that they're hidden in the gclid. The 'gclid= StrangeGibberishHere123' contains all the information Analytics needs to assign 'campaign', 'ad group', 'placement' etc., so having 'utmccn' and 'utmcmd' set on top of that would just confuse things.

Also, having information hidden in a 'gclid' and not in 'utmcmd' means competitors can't just look at the cookies set on their computers to determine your AdWords account structure.

Another question we were asked was:

"When I look at Analytics Real Time, I see active pages tagged with things like /landingpage.html?gclid=blahblahblah – what's going on?"

When someone clicks on an ad, they'll actually go to the URL /landingpage.html?gclid=blahblahblah. Usually Analytics would strip away the gclid parameter and show just /landingpage.html as the page – but the gclid still shows up in Analytics Real Time, presumably because Real Time is only in beta.

But what are your thoughts? Have you had similar queries thrown at you and have you got any insights to share? Please feel free to add to the discussion within the comments below.