Basic characteristics used for audience segmentation, such as age, gender or household income, marital status, location, etc. Understanding the demographics of a target audience is essential for an Internet marketing plan. In the media buying process, understanding the demographics of a site (or group of sites) is critical to the site selection process. Advertisers will look at site demographics to help them decide which sites are effective at reaching their target audience (audience composition). Demographic data can come from the syndicated research companies (e.g. from comScore or NetRatings) or from sites that conduct their own proprietary readership studies.