Out-of-home advertising (OOH), also known as outdoor advertising, is a form of advertising that can be found outside of a consumers home. It includes billboards, wallscapes, posters, street furniture, transit, and alternative media seen in places such as convenience stores, medical centers, salons, and other brick-and-mortar venues. OOH advertising formats fall into four main categories: billboards, street furniture, transit, and alternative.

OOH advertising is a powerful tool for advertisers and marketers because it can have a significant impact on consumers. OOH campaigns cant be ignored, compared to TV, radio, or mobile, which can often be turned off, or the consumer can move to another channel. The benefits of OOH advertising include the potential to reach a new audience or reinforce the messaging of a wider campaign. OOH advertising can be successfully incorporated into marketing activity at all levels, from full-scale national brand campaigns to local lead-gen efforts.

The main types of OOH ads are billboards, street furniture, POS displays, bus shelters, kiosks, and telephone boxes. Traditional roadside billboards remain the predominant form of OOH advertising in the US with 66% of total annual revenue. Today, billboard revenue is 73% local ads, 18% national ads, and 9% public service ads. Tech companies like Facebook and Google are leading the way in the world of online advertising, yet when they want to spread the word about their newest product or feature, they turn to OOH advertising, buying billboard ads around the world.

OOH advertising is an expansive category, and today represents spending of about $29 billion across key markets around the world. Some of the worlds most important advertisers, including McDonalds, Apple, Amazon, HBO, and Coca-Cola, all make regular and extensive use of various OOH formats in their campaigns.