From Wikipedia

The Nude In Art

Episode Four

In modern media, images of partial and full nudity are used in advertising to draw additional attention. In the case of attractive models this attention is due to the visual pleasure the images provide; in other cases it is due to the relative rarity of images of nudity. The use of nudity in advertising tends to be carefully controlled to avoid the impression that the company whose product is being advertised is indecent or unrefined. There are also limits on what advertising media such as magazines allow. The success of sexually provocative advertising is claimed in the truism "sex sells". However, responses to nudity in American advertisements have been more mixed; nudity in the advertisements of Calvin Klein, Benetton, and Abercrombie & Fitch, to name three companies, have provoked much negative as well as positive response. (See also: Sex in advertising).

Of images of nudity (not necessarily pornographic), the most extreme form is full frontal nudity, referring to the fact that the actor or model is presented from the front and with the genitals exposed. Frequently images of nude people do not go that far and photos are deliberately composed, and films edited, such that in particular no genitalia are seen, as if the camera failed to see them by chance. This is sometimes called "implied nudity" as opposed to "explicit nudity."