Conducted by independent and objective third-party measurement companies, there is no conflict of interest. Because user-centric systems are generally based on panels it also can provide detailed information about the demographic characteristics of users and their cumulative use of online media over time, including reach and frequency of exposures. Due to the finite resolution of any sample-based technique, it has difficulty providing detail about activity below the domain level of Web sites. Because of the fragmentation of the World Wide Web, many meaningful sites cannot be cost-effectively measured at all. An aggregator or broker of advertising inventory from many sites.
Browsers can be either text or graphic.
They read HTML-coded pages which reside on a server and interpret the coding into what we see as Web pages. Netscape Navigator and Internet Explorer are examples of Web browsers. Servers, which deliver Web pages or ads, can introduce techniques to minimize or eliminate other computers from storing their pages or banners. Most ad servers do not allow caching so that ads served can be properly measured and targeted to the visitor making the request. The address or URL of a particular Web site.