Publications of this kind may contain images of attractive naked subjects, as is the case in softcore pornography ,  and, in the usual case of hardcore pornography , depictions of masturbation , oral or anal sex, or intercourse. They primarily serve to stimulate sexual arousal , and are often used as an aid to masturbation. Well-known adult magazines include Playboy , Penthouse and Hustler. Magazines may also carry articles on topics including cars, humor, science, computers, culture and politics. With the continued progression of print media to digital, retailers have also had to evolve.