A range of tools exist to break down and understand the traffic (visitors to) websites. This traffic analysis is crucial to Internet marketers as it allows them to not only understand the sources of their visitors but a great deal of detail about their user behaviour.
Some public sites such as Alexa attempt to provide rankings and information about user behaviour and site traffic globally. This is a task fraught with difficulties and potential statistical bias (such as over-reliance on certain toolbar users). It does, however, illustrate well the importance of understanding not only how many users visit a site but the behaviour of that traffic also.
Webmasters have significantly more powerful tools available to them when analysing the traffic on their own site – including tools such as Google Analytics. They can see in detail how traffic arrived at pages on the site as well as how that traffic then flowed through the site, what pages were visited and for how long before the traffic eventually moved on. This gives designers and marketers a clear idea of what pages are working and important to users to further optimise their campaigns.