role of advertising
Online advertising is a form of promotion that uses the Internet and World Wide Web for the expressed purpose of delivering marketing messages to attract customers. Examples of online advertising include contextual ads on search engine results pages, banner ads, Rich Media Ads, Social network advertising, online classified advertising, advertising networks and e-mail marketing, including e-mail spam.
 Billboard advertising
Billboards are large structures located in public places which display advertisements to passing pedestrians and motorists. Most often, they are located on main roads with a large amount of passing motor and pedestrian traffic; however, they can be placed in any location with large amounts of viewers, such as on mass transit vehicles and in stations, in shopping malls or office buildings, and in stadiums. Mobile billboard advertising
Mobile billboards are truck- or blimp-mounted billboards or digital screens. These can be dedicated vehicles built solely for carrying advertisements along routes preselected by clients, or they can be specially-equipped cargo trucks. The billboards are often lighted; some being backlit, and others employing spotlights. Some billboard displays are static, while others change; for example, continuously or periodically rotating among a set of advertisements.
Mobile displays are used for various situations in metropolitan areas throughout the world, including:
- Target advertising
- One-day, and long-term campaigns
- Sporting events
- Store openings and similar promotional events
- Big advertisements from smaller companies
 In-store advertising
In-store advertising is any advertisement placed in a retail store. It includes placement of a product in visible locations in a store, such as at eye level, at the ends of aisles and near checkout counters, eye-catching displays promoting a specific product, and advertisements in such places as shopping carts and in-store video displays.
 Covert advertisingMain article: Product placement
Covert advertising, also known as guerrilla advertising, is when a product or brand is embedded in entertainment and media. For example, in a film, the main character can use an item or other of a definite brand, as in the movie Minority Report, where Tom Cruise's character John Anderton owns a phone with the Nokia logo clearly written in the top corner, or his watch engraved with the Bulgari logo. Another example of advertising in film is in I, Robot, where main character played by Will Smith mentions his Converse shoes several times, calling them "classics," because the film is set far in the future. I, Robot and Spaceballs also showcase futuristic cars with the Audi and Mercedes-Benz logos clearly displayed on the front of the vehicles. Cadillac chose to advertise in the movie The Matrix Reloaded, which as a result contained many scenes in which Cadillac cars were used. Similarly, product placement for Omega Watches, Ford, VAIO, BMW and Aston Martin cars are featured in recent James Bond films, most notably Casino Royale. In "Fantastic Four 2: Rise of the Silver Surfer", the main transport vehiche shows a large Dodge logo on the front. Blade Runner includes some of the most obvious product placement; the whole film stops to show a Coca-Cola billboard.
 CelebritiesMain article: Celebrity branding
This type of advertising focuses upon using celebrity power, fame, money, popularity to gain recognition for their products and promote specific stores or products. Advertisers often advertise their products, for example, when celebrities share their favourite products or wear clothes by specific brands or designers. Celebrities are often involved in advertising campaigns such as television or print adverts to advertise specific or general products.
 Media and advertising approaches
Increasingly, other media are overtaking many of the "traditional" media such as television, radio and newspaper because of a shift toward consumer's usage of the Internet for news and music as well as devices like digital video recorders (DVR's) such as TiVo.
Advertising on the World Wide Web is a recent phenomenon. Prices of Web-based advertising space are dependent on the "relevance" of the surrounding web content and the traffic that the website receives.
Digital signage is poised to become a major mass media because of its ability to reach larger audiences for less money. Digital signage also offer the unique ability to see the target audience where they are reached by the medium. Technology advances has also made it possible to control the message on digital signage with much precision, enabling the messages to be relevant to the target audience at any given time and location which in turn, gets more response from the advertising. Digital signage is being successfully employed in supermarkets. Another successful use of digital signage is in hospitality locations such as restaurants. and malls.
E-mail advertising is another recent phenomenon. Unsolicited bulk E-mail advertising is known as "spam". Spam has been a problem for email users for many years. But more efficient filters are now available making it relatively easy to control what email you get.
Some companies have proposed placing messages or corporate logos on the side of booster rockets and the International Space Station. Controversy exists on the effectiveness of subliminal advertising (see mind control), and the pervasiveness of mass messages (see propaganda).
Unpaid advertising (also called "publicity advertising"), can provide good exposure at minimal cost. Personal recommendations ("bring a friend", "sell it"), spreading buzz, or achieving the feat of equating a brand with a common noun (in the United States, "Xerox" = "photocopier", "Kleenex" = tissue, "Vaseline" = petroleum jelly, "Hoover" = vacuum cleaner, "Nintendo" (often used by those exposed to many video games) = video games, and "Band-Aid" = adhesive bandage) â¬" these can be seen as the pinnacle of any advertising campaign. However, some companies oppose the use of their brand name to label an object. Equating a brand with a common noun also risks turning that brand into a genericized trademark - turning it into a generic term which means that its legal protection as a trademark is lost.
As the mobile phone became a new mass media in 1998 when the first paid downloadable content appeared on mobile phones in Finland, it was only a matter of time until mobile advertising followed, also first launched in Finland in 2000. By 2007 the value of mobile advertising had reached $2.2 billion and providers such as Admob delivered billions of mobile ads.
More advanced mobile ads include banner ads, coupons, Multimedia Messaging Service picture and video messages, advergames and various engagement marketing campaigns. A particular feature driving mobile ads is the 2D Barcode, which replaces the need to do any typing of web addresses, and uses the camera feature of modern phones to gain immediate access to web content. 83 percent of Japanese mobile phone users already are active users of 2D barcodes.
A new form of advertising that is growing rapidly is social network advertising. It is online advertising with a focus on social networking sites. This is a relatively immature market, but it has shown a lot of promise as advertisers are able to take advantage of the demographic information the user has provided to the social networking site. Friendertising is a more precise advertising term in which people are able to direct advertisements toward others directly using social network service.