It is impossible to count up quantity of site visitors precisely by using IP-addresses. It is stipulated by the fact that many users use corporate access to the Internet and when they get access to the network they receive the same IP-address (the corporate "proxy" IP-address, i.e. an intermediary server). The same is true for users of some public systems of access to the Internet (house networks, systems of telephone dialling) - users are assigned different IP-addresses each time or one IP-address is appointed to all.

          Cookie technology is used in the Internet for more exact calculation of visitors and for recognition of the same visitor in its iterated entering your site (in English translation it is read as cookies, pastry) and consists in the following.

           At the first visiting of a site user browser is appropriated by the unique cookie-identifier - as a matter of fact, it is just a simple text line with the web server data.

           At the subsequent viewings of site pages the browser, on the contrary, informs this identifier to the site which has given it out (and to it only). Thus, it is possible to trace both the several users coming from one IP-address and one user coming from different IP-addresses.

          This method is the only way to trace the behavior of site visitors for the majority of sites at present site (without their registration and the subsequent input of login and password).

          At the same time, from 10 to 30 % of users clear (or lose) cookie records within a month according to modern estimations. It leads to the overestimation of the new user quantity estimation as it was already mentioned above.