Google Instant Pages Prerendering Can Inflate Analytics Stats

google-instant-pages-relevance-prerenderingThe recent launch of Chrome 13 had a few new features, one of which, Instant Pages, seems to be creating problems for analytics programs. The new prerendering of pages in the background while you search seems to create pageviews even if the page isn't clicked on in the search results.

While some have come out and said the prerendering won't skew analytics - one wonders if that is just the case for Google Analytics and even then if certain things have been done to stop erroneous inflation of pageview counts.

Google says there is a “small possibility” Chrome can cause inflated pageview Analytics stats: when Google’s experimental Page Visibility API returns a false positive because a document is visible in the browser but is obscured by another window, and when Google prerenders the wrong page.

"Most website analytics solutions assume that one page load is equivalent to one user 'impression,' or page view. Although google.com only issues the prerender hint when it is confident that it knows where the user will click, in some cases it will mispredict, resulting in a page that has appeared to load but was never actually shown to the user," a Google spokesperson told WebProNews. "Although this will happen relatively rarely, in some cases it is important for the webpage to know.

"Chrome has implemented a new API called the page visibility API that, among other things, allows websites to detect when they're being prerendered."

So while Google Chrome is using this, any numbers from this browser could be considerably inflated - with Chrome's growing market share this will only increase. The bigger issue is what will other analytics programs do? Google may be able to provide an internal workaround for their analytics, but what of others? Is Google making a backdoor play for more analytics users?

Interesting that Google expects other analytics firms to make changes to their programming to meet the Chrome feature impact.

"Analytics and advertising solutions will have to be updated to take account of prerendering via the page visibility API. In most cases the end site owner shouldn't have to make any modifications to his page; the 3rd party will simply make a minor change to the javascript that is pulled into publishers' pages," the Google spokesperson told WebProNews. "You should check with your analytics or advertising providers to check if their scripts are prerendering-aware."

As a GetClicky spokesperson explained, the prerendering includes JavaScript execution and thus will trigger the tracking code. Countering it would require the adding of code to see if this is a prerender request through a special Chrome accessibility property, which would then have to be added to any tracking code.

It's still to early to know how this will impact other aspects of analytics. But this issue does raise the question: why does Google think this type of speedy delivery is needed?

Another impact will be changing the code on your pages if you are not using GA and the other analytics program makes the required changes to the code - it still needs to be implemented on your pages, unless it can all be done on the server side when they see the browser info and request whether it is viewed or just prerendered.

Sound like Google is creating potential headaches for the other analytics companies.

Another problem can arise for people with limited bandwidth usage as the prendering will add to that total.

Will this last or will the problems be overcome? And do we really need this?

About the author

Frank Watson has been involved with the Web since it started. For the past five years, he headed SEM for FXCM -- at one time one of the top 25 spenders with AdWords. He has worked with most of the major analytics companies and pioneered the ability to tie online marketing with offline conversion.

He has now started his own marketing agency, Kangamurra Media. This new venture will keep him busy when he is not editing the Search Engine Watch forums, blogging at a number of authoritative sites, and developing some interesting online community sites.

He was one of the first 100 AdWords Professionals, a Yahoo and Overture Ambassador, and a member or mod of many of the industry forums. He is also on the Click Quality Council and has worked hard to diminish click fraud.