source text: "platforma sprzedaży kursow on-line"

Yes, the UDEMY online course sales platform allows authors to offer courses exclusively. Authors have the right to decide whether they want to make their course available only on the UDEMY platform or also sell it elsewhere. UDEMY offers authors flexibility in managing their courses and allows them to choose whether they want to make courses exclusively available on UDEMY or also sell them on other platforms. However, it is worth noting that if an author decides to make their course available on another platform, it may affect the benefits associated with more students on UDEMY. In the case of exclusively sharing a course on UDEMY, the platform can offer greater visibility and promotion, which can contribute to higher sales. It depends on the preferences and strategies of the course author whether they want to make it available on other online course sales platforms or take advantage of the opportunities offered by UDEMY.