Google announced this week that the new Google AdPlanner, a marketing research and media-planning tool, is now available to the public in beta form. I was approved to use it late last night, and when I finally got in there this morning, it was surprising to see the depth of information the site gives you about hundreds of sites within the Google Content Network. If you do any form of online advertising, this should be your first stop for information not only because it is free, but also because the information offered is equivalent to other paid service.

Through Google AdPlanner, users can filter sites by demographic factors such as gender, age, education and household income. If you do a lot of advertising in placement campaigns through Google AdWords, it is helpful since the demographic filters on the content network sites here leaves something to be desired.

You can also work backwards through the application, choosing a competitors site and getting information like similar sites, user demographics and traffic estimates. The tool allows you to create a list of the sites you want to incorporate in your ad campaign; you can export the information into a .csv file for later use.

And while you may pay for a similar marketing research tool, Google AdPlanner is still a simple, valuable, yet free tool that every Internet marketing company should check out. With so many additional features I didn’t mention here, it warrants attention from media planners and search engine marketers in every industry.