Google Website Optimizer May Cause Search Penalties

Ian Lurie

Google Website Optimizer lets you test various headlines, product shots and other page elements against each other. And it’s free. Wouldn’t you always want to use it?

No – ironically, Google’s Website Optimizer engages in a practice that some call ‘cloaking’. That practice may lead to search ranking penalties from – you guessed it – Google. Google’s own Matt Cutts has a great summary of the tactic here.

Optimizer causes your web browser to replace parts of the page you’re viewing, like so:

Google Website Optimizer: Variation 1
Google Website Optimizer: Variation 2

In the above images, my browser replaced ‘Your Child Deserves the Best’ with ‘Attend a Free Kindermusik Class’. It also swapped out a regular-weight ‘for free’ for a bolded ‘for free’. Google’s tool did this on the fly, using javascript.

I’ll skip the geeky details. Suffice it to say that using javascript to swap out one piece of content for another on the page is a fairly common, unethical search engine optimization tactic. Spammers use the technique to show one version of their content to search engines and another to users. Search engines like Google put a lot of energy into detecting and penalizing sites that employ this tactic.

So, by using Google Website Optimizer, you can actually end up being penalized by Google, as well as Yahoo and MSN.

However, all is not lost. Here’s how you can use the optimizer without getting into trouble:

  1. Use it only on separate landing pages. If you create special pages that visitors can only reach from paid search results, e-mail campaigns or banner ads, then search engines can’t ‘crawl’ their way to those pages. It’s safe to use the Website Optimizer there, because search engines won’t find those pages.
  2. Add a meta tag. You can tell search engines not to crawl specific pages on your site with the META ROBOTS tag: <meta name=“robots” content=“noindex”>. If this is gobbledygook to you, get your web developer or webmaster to set it up. By using this tag on any pages where you’re using Google’s optimizer tool, you’ll keep yourself out of trouble.
  3. You should use this meta tag even on separate landers, because someone might link to those landing pages from their sites, thereby pointing them out to the search engines.

Everything I’ve seen so far tells me Google’s Website Optimizer is a fantastic tool. But like all tools, it makes sense to use it judiciously. Be mindful of the potential issues, protect yourself against potential cloaking penalties, and you’ll be fine.

Ian Lurie

Ian Lurie is the founder of Portent. He's been a digital marketer since the days of AOL and Compuserve (25 years, if you're counting). Ian's recorded training for, writes regularly for the Portent Blog and has been published on AllThingsD, Smashing Magazine, and TechCrunch. Ian speaks at conferences around the world, including SearchLove, MozCon, Seattle Interactive Conference and ad:Tech. He has published several books about business and marketing: One Trick Ponies Get Shot, available on Kindle, The Web Marketing All-In-One Desk Reference for Dummies, and Conversation Marketing. Ian is now an independent consultant and continues to work with the Portent team- training the agency group on all things digital. You can find him at

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  1. Ian,
    Although you bring up a valid concern, there is no indication that Google will charge you for as though you were “cloaking” (the dirty SEO tactic in question) your site.
    If you’d like a better understanding of the mechanics of using this tool from Google Website Optimizer’s perspective, we recently hosted a podcast interview with Google’s Tom Leung on the subject.
    In the interview, Tom explicitly details how one’s rankings are affected. There’s no way your site would get charged for “cloaking.” If so, this would have been a problem for anyone conducting A/B or multivariate tests in the past.

  2. Hi Robert,
    I believe you. However, Google isn’t the only game in town. Getting dinged on Yahoo and/or MSN wouldn’t be much fun.
    Also, I love Google, but they’ve been known to err on occasion…

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