The basic definition is that these are not original posters printed for promotional purposes. Commercial posters are made by various poster companies that acquire the license
to mass produce posters on a certain celebrity, movie, musical artist, etc. They print large quantities for maximum distribution and to achieve a lower retail price. The size of commercial posters varies - 22x34, 23x35, 24x34, 24x36, 25x36, depending on the company producing them.