1、外文文献 The Online Advertising Industry Advertising delivered over the internetonline advertisinghas become a significant source of revenue for web-based businesses. Fifty-six of the top 100 websites based on page views in February 2008 presented advertising； these 56 accounted for 86 percent of
2、the total page views for these 100 sites. Twenty-six of these 56 sites, accounting for 77 percent of all page views for the top 100 sites, likely earn most of their revenue from selling advertising. Advertising is a significant source of revenue for many of the smaller sites including ones such as b
3、logs that occupy the long-tail of the web. Online advertising is also central to the $34 billion e-commerce economy, which is becoming an ever larger portion of overall commerce. Web-based sellers use online advertising to drive consumers directly to their sites where they can browse for goods and s
4、ervices and purchase them with a few clicks. Online advertising accounted for 8.8 percent of all advertising in the United States in 2008. That share is expected to grow as people spend more time with new online media such as social networking and sites that offer user-generated content； as more tra
5、ditional media such as television is transmitted over the internet； and as more advertising is delivered to browser-enabled mobile phones. Internet-based advertising is the source of a gale of creative destruction .that is sweeping across the advertising and media landscape, especially in the United
6、 States. Newspapers, particularly, are losing readers and advertisers to web media supported by online advertising. That has lead to a downward spiral as indirect network effects work in reverse. The market caps of the major publicly traded newspaper businesses in the United States declined by
7、 42 percent between January 2004 and August 2008, compared to a 15.6 percent increase for the Dow Jones Industrial average over that same time period. With the additional pressure of the financial crisis, newspapers in several major cities including Denver and Seattle have closed down and others inc
8、luding the New York Times are in distress. More generally, online advertising is disrupting all aspects of the global advertising industry, which had estimated revenues of $625 billion in 2007, from how creative work is done, to how advertising campaigns are run, and to how advertising is bought and
9、 sold. Online advertising methods are, arguably, leading to significant reductions in transactions costs between merchants and consumers. The methods enable merchants to deliver information that is targeted to those consumers who value the information the most and are most likely to act on it.
10、 An oft-quoted line in the advertising business states ruefully: Half the money I spend on advertising is wasted. The only trouble is I dont know which half. The new techniques replace a sledgehammer with a scalpel. In doing so, they collect and analyze detailed information about how people use thei
11、r computers raising difficult issues concerning the expectation of privacy and the regulation of the online advertising industry. No research has yet examined the value of the productivity improvements created by online advertising technology but they appear significant. Consider a business that sel
12、ls saltwater fishing rods to people who enjoy fly fishing. The traditional approach to matching this buyer and seller involved the creation of a magazine, such as FlyFisherman, with content that attracts the relevant people. In contrast, the online approach relies on a variety of techniques to match
13、 an advertising message to a consumer. A search engine indexes web results that are relevant to a consumer who types in the phrase saltwater fishing rod, and with this information, the search engine can sell ads to sellers of saltwater fishing rods. Contextual advertising on web pages could do the s
14、ame thing. A consumer who visits a blog for fly fishermen could be presented with an advertisement. Developing behavioral targeting techniques, discussed below, can also identify individuals who are interested in fly fishing and determine whether they are looking around the web for information that
15、would suggest they might be in the market for a saltwater rod. This essay presents the evolution of the online advertising business. It examines the supply of online advertising inventory, which equals the space times the views of that space； the demand for that inventory； and intermediaries that op
16、erate between the sell and buy sides. It also explores some of the key developments such as behavioral targeting for matching advertising messages to consumers and considers some economic aspects of the privacy issues that these technologies raise. Aside from providing a survey of an important new s
17、egment of advertising this essay suggests, at various points, that many of the interesting questions, and economic puzzles, about the advertising industryoffline and onlineremain to be addressed.for example, online advertising is a two-sided market, as is advertising generally. Intermediaries operat
18、e platforms that facilitate advertisers and consumers connecting with each other. The fundamental differences between online and traditional advertising result from a combination of internet technologies and the nature of the web. The structure of online communications makes it easy for publis
19、hers and ad networks to learn considerably more about online users than has been possible with traditional media such as print, radio, and television. Online media or their ad networks typically know for certain from the internet technologies for linking people to sites that an individual is viewing
20、 their site. That is very different from a radio station, or a newspaper, which have limited ability to determine whether a particular individual is listening or reading. Online media can often learn valuable details about the individual that has signed on to the site. Each user has an IP address wh
21、ich typically identifies the location of the individual down to at least the zip code level in the United States. People who browse from home and from smaller companies typically have a unique IP address that remains the same over time.Using this address it is possible for online media and advertisi
22、ng networks to track other sites that users with that IP address have visited and to match up other details about the individual or household.In addition, individual websites, such as and , may have detailed information on registered users which they can also use for advertising. Print, radio and television media generally do not know this level of information for individual users； Cable systems with set-top boxes also have specific information on viewers but do not have ready access to the browsing behavior of those individuals. Traditional
