Google has purchased San Diego based web analytics firm Urchin for an undisclosed amount of cash and/or stock. Urchin is a web site analysis tool that allows users to study the habits of site visitors in order to get a better view of what they are doing when they visit a particular site. Understanding the experiences of site visitors allows webmasters to track the performance of their websites and better optimize content to meet the wants and needs of those visitors. Currently, Urchin tools are available as hosted services (run from, software packages (run from user’s computer), or as the default site-stat service offered by many larger ISPs.

Google plans to make Urchin stats available to website publishers and AdWords advertisers. “We want to provide web site owners and marketers with the information they need to optimize their users’ experience and generate a higher return-on-investment from their advertising spending,” said Jonathan Rosenberg, vice president of product management, Google. “This technology will be a valuable addition to Google’s suite of advertising and publishing products.”

As a feature for AdWords advertisers, Urchin analytics will let search engine marketers know exactly how viewers react to specific landing pages. For example, if sales are bad but visits are very high, perhaps a minor redesign of the page will help convert sales.

Similarly, organic placement advertisers can track how a site visitor moves from the Home page (the most likely to achieve numerous placements) through the site. This information might make all the difference between a commercially successful business site and one that produces the income of a part-time job.

If Google opens Urchin up for both AdWords and Organic placement advertisers, chances are it will become a standard tool for measuring and analysing user behaviours, at least for SEO and SEM practitioners.