The present invention relates to a system for measuring audience of media on at least one communication network like an Internet communication network. The audience measurement system operates on a collection of networks comprising at least one communication network. A plurality of predetermined users is associated with a first suite of machines (D, LT) connected to a network of the said collection of networks, in a first zone of use and with at least one second suite of machines (AL) connected to a network of the said collection of networks, in a second zone of use. The system of the invention consists in that a calculation means (M1-M5) is designed to produce, on the basis of the first suite of machines, user counterparts for at least one other zone of use (AL) so as to reconstitute the plurality of the users.