Mobile billboard is the marketing practice of advertisement on the side of a truck or trailer that is typically mobile. Mobile billboards are a form of Out-Of-Home advertisement. Radio, static billboards, and mall/airport advertisement fall into the same category. Using a mobile billboard for advertisement is an advertisement niche called Mobile Outdoor advertisement.

Most mobile billboards are dedicated, customized trucks with large, but narrow, bodies for posting the advertisements. Some of these dedicated units offer features such as external sound systems, illumination, and hot/cold boxes for product sampling. This type of mobile billboard is the most popular among vendors, and the most capable in terms of gaining exposure and quick deployment.

Some mobile billboards are installed on trucks and trailers that are in service delivering goods. This form of mobile billboards can be less expensive than dedicated trucks, but may also have less impressions because the trucks spend more time at docks loading and unloading their goods.

Box-type trucks with glass panels enclosing the cargo space can be turned into a 3-D display. Many companies use these trucks for parades, product launches, furniture displays, and general rapid awareness creation. Anything can be placed inside of the boxes.

Bus advertising is a popular way for advertisers to reach the public in metropolitan areas. Ads are placed in bus shelters or on the backs of benches at stops. Inside the bus, ads are sometimes attached to the corners between the walls and ceiling overhead, or on monitors throughout the vehicle. Externally, placards known as "boards" can be placed on the front, sides, and rear of a bus.

The municipality will often sell the rights to place advertising on public property to a media provider. A client will ask for a board to promote its product or approve the recommendation of the advertiser. An advertiser then asks a media broker to arrange for the purchase. The broker coordinates with the advertiser and the provider and collects a commission. The provider keeps the difference between what it collects and the payments it makes to the government agency.

from : wikipedia.org