How does Google's 'site interaction tracking' affect rankings?

• I've heard that Google tracks how site visitors interact with a site and factors their behavior into the rankings. Is this true? ...and if so, what are the specifics?

Answer: What you're referring to is loosely called Historical Performance of a Site. And, although Google has never confirmed this metric within their algorithm, it is reasonable to assume that they measure:

1. Bookmarks
2. Clickthroughs from SERPs
3. Time spent on page before clicking back
4. Visitors who enter URLs directly into the browser's location box

...and perhaps many more behavioral aspects of web users that we aren't even aware of.

In light of the fact that Google has in place several ways to track and collect this data, it would be downright silly for them not to factor these ingredients into the soup. Obviously whenever you are logged into your Google account, they are collecting information specific to your online activity. In addition, the Google Toolbar is a convenient way for them to spy on...uh, monitor the behavior of web surfers. Google Analytics is another potential measuring tool. And then, of course, they have the data from the search engine results pages (SERPs) that tells them what search results people are clicking on in relation to specific keyword queries.

Perhaps most potentially useful to Google as a data collection instrument is their newly released browser, Google Chrome. We can only imagine the vast opportunity that Chrome presents to Google as a way to (anonymously?) track the habits and behaviors of how people search and use the web—and then blend these nuances into their ranking algorithm.

Nevertheless, it's important to note that Google has never publicly admitted any of these factors are part of their secret sauce. Regardless, we suggest that you treat them as real and plan accordingly. That means that you should:

• Make sure your site's theme very obviously matches the keywords in the search query being used to find your site. This is important beca...