Reaction to Google Trends for Websites, however, has the added dimension of users being very upset about a perceived breach of confidence, because users assume (and have no reason not to) that Google Analytics data is one of the varied sources of input from which traffic estimates are calculated.
While Google Trends has been showing trends in keyword demand since 2006, the ability to view estimated site traffic is its biggest update so far.
At first, some people jumped the gun and believed that the data came straight from Google Analytics. This is incorrect, as Google Trends shows traffic estimates even for sites that don't use Google Analytics.
The rationale for being a little disturbed about such a tool is still understandable, especially with the growing number of sites that utilize Google Analytics. After all, signing in to your Google Analytics account requires a password, from which one can infer that preventing the "wrong" user from accessing the data is important to Google. The sudden release of information that is similar to Google Analytics data has users wondering whether that privacy really is important to Google.
On the other hand, many people have pointed out that services like Alexa, Hitwise, and comScore already offer similar traffic estimates with little or no objection from the masses. Of course, the counter to that argument is that Web sites typically provide no information directly to these third parties in the way that many of them offer analytics data to Google.
Love it or hate it, right now there's little you can do to hide your site's statistics, short of taking your site offline. Even excluding your site via robots.txt would probably do little good because Google uses "a variety of sources" to estimate traffic.
To make the tool valuable to you, the first thing you should do is contrast what Google Trends says about your site's traffic with your site's actual traffic. (If your site doesn't show up yet in Google Trends, it's because a site needs to achieve a certain, undefined threshold of visits before it will show up on the Trends radar. I hope this threshold will become lower over time.) Don't be concerned with actual numbers matching up. Instead, watch to see whether the peaks, valleys, and flat periods in Google Trends correspond to your own site's data.
If the two data sources have lines that look similar when you overlay one to another, then it becomes more likely that the data is fairly reliable. Google is very "vertically" oriented (as proven by their close monitoring of sites "related" to the sites in a Trends report), so it's likely that other sites in your vertical will have Google Trends traffic reporting that are roughly as accurate (or inaccurate) as reports for your own site.
Start watching your competitors' sites closely, including their AdWords campaigns, any on-site SEO efforts, or third-party advertising. Compare those initiatives with their Google Trends traffic reporting to see how worthwhile those efforts were for them. In addition, look closely at the "Also Searched For" list of terms, and make sure that you're integrating those into your keyword strategies, if the terms are at all applicable.
You might be unhappy about Google showing traffic data for sites, or you might not care. Regardless, it's probably not going away soon, so settle back and learn how you can make it work for your site.
Erik Dafforn is the executive vice president of Intrapromote LLC, an SEO firm headquartered in