It's based on use. Under our system, teachers have to report the works that are being used so that rights holders can be as fairly compensated as possible. The more often their work is reproduced, the more remuneration they receive.
We issue a cheque for a minimum of $25, but the maximum can be as high as several thousand dollars, depending on how much the work is used. There is an exception for exams, but when a work is used for a mandatory French exam and 70,000 copies are made in Quebec, an author can expect to receive several thousand dollars for the use of his or her work in that context. That will became an exception under Bill C-32.