If you’re launching a new product or service, it can be tough to gain insight into your targeted user. One way to do it is to find information about other sites that you would assume your target would use.

One way to do that is to use a service like Quantcast. Quantcast is a free internet ratings system, generating traffic statistics and audience make-up for millions of registered web sites and blogs. The system measures visitor characteristics like gender, age, ethnicity, education, and income, as well as popularity and frequency of your site and any featured media. Quantcast is able to do this by blending panel-based estimates (sampling a small portion, then extrapolating larger data) and direct information from “tagged” sites.

If you don’t have a large site or one that’s already been tracked, you can simply use this service to identify a large, but similar site. You’ll find all sorts of interesting demographic and tracking information that you can then use to inform your own decisions.

To join the fun (and have your site added to the database), submit your url and site description to Quantcast, stipulating what information you would like to be public. The system will generate a personalized tag to be placed in your website code and any flash-based media you would like to measure, whether it’s a video, widget, or game. Quantcast will begin measuring your site immediately, providing metrics like play and reach for your media, even if it’s served on sites other than your own.