Outdoor advertising (also referred to as OOH) is essentially any type of advertising that reaches the consumer while he or she is outside the home. This is in contrast to broadcast, print, or internet advertising, which may be delivered to viewers out-of-home (e.g. via tradeshow, newsstand, hotel lobby room), but are usually viewed in the home or office. Outdoor advertising products are divided among four primary categories: billboards, street furniture, transit and ambient. OOH encompasses outdoor advertising but extends to the indoors as well (such as ads in shopping centres and malls).