Online Advertising: Defining Relevant Markets1 James D. Ratliff* and Daniel L. Rubinfeld† ABSTRACT This paper provides an overview of the development of Internet advertising. We offer a broad overview of both online and offline advertising and the economic models that allow one to evaluate competition among advertisers. We focus on the extent to which various types of online advertising compete with each other and with offline advertising. We also ask whether various types of online ads are competitive with each other. JEL Code: L86 1 This study was supported by funding from Google. The authors have no prior involvement in any Google matters. The opinions are solely those of the authors and do not necessarily reflect the views of Google. We wish to thank Hal Varian for his helpful comments throughout. * Compass Lexecon, [email protected] † School of Law and Department of Economics, U.C. Berkeley Market Definition in Online Advertising I. INTRODUCTION The rapid growth of the Internet, and the incredible flow of information that the Internet has made possible, has transformed the business of advertising.2 Today it is difficult to surf the web without seeing online advertising, often in the form of visual display ads on web sites (including pop-ups and pop-downs) and textual ads on search sites.3 There is little doubt that on-line advertising has taken business away from traditional modes of advertising, such as newspapers, snail mail, and radio. What is less clear is whether the shift is price driven and whether traditional advertising channels constrain the pricing of Internet ads. This paper provides an overview of the development of Internet advertising. In the process, we describe the nature of advertising competition as it currently exists online. We focus on the extent to which various types of online advertising compete with each other and with offline advertising. While our goal is not to reach a definitive opinion as to how relevant markets ought to be defined, we do suggest a number of core empirical questions whose answers will help to clarify questions surrounding market definition.4 The paper proceeds as follows. In Section II, we describe the birth and growth of the Internet and online advertising. Section III offers a broad overview of both online and offline advertising and the economic models that allow one to evaluate competition among advertisers. In Section IV, we focus on online advertising and distinguish the various types of online ads and the means by which those ads are marketed. Section V focuses on competitive issues. We evaluate the extent to which online and offline ads compete and we also ask whether various types of online ads are competitive with each other. In Section VI, we offer some brief concluding comments and suggestions for further research. II. THE ORIGIN AND GROWTH OF ONLINE ADVERTISING A. The Birth and Commercialization of the Internet The intellectual and technical underpinnings of the Internet go at least as far back as the very early 1960s, when MIT’s J.C.R. Licklider coauthored a trilogy of memos describing the “Galactic Network” concept5 and Leonard Kleinrock, also of MIT, published the seminal paper on packet-switching theory.6 These cornerstones led in 1972 to the first public demonstration of the ARPANET (Advanced Research Projects Agency Network)—the precursor of today’s Internet—and to the introduction of electronic mail. By 1985, the …7 Internet was already well established as a technology supporting a broad community of researchers and developers, and was beginning to be used by other communities for daily computer communications. Electronic mail was being used broadly across several communities, often with different systems, but interconnection between different mail 2 Lower-case-i “internet” originally referred to any network of networks. (Debra Littlejohn Shinder, Computer Networking Essentials, CISCO PRESS, 37 (2001).) Upper-case-I “Internet” refers to “the global information system that is logically linked together by a globally unique address space based on the Internet Protocol (IP)….” (Federal Networking Council, FNC Resolution: Definition of “Internet,” (October 24, 1995), at http://www.nitrd.gov/fnc/Internet_res.html). Usage has been moving in the direction of using lower-case-i internet to refer to the global network. (See examples at Internet capitalization conventions, at http://en.wikipedia.org/wiki/Internet_capitalization_conventions). 3 The benefits of advertising can also be achieved when information about the business appears on the list of “organic results” displayed by the search engine. 4 Market definition is a means to an end—to a competitive analysis of a merger or of a non-merger activity. As a result, a market definition exercise outside the merger context will sometimes deviate substantially from the exercise that would be undertaken if there were a merger. 5 J.C.R. Licklider, Man-Computer Symbiosis, (HFE-1) IRE TRANSACTIONS ON HUMAN FACTORS IN ELECTRONICS 4-11 (March 1960) at http://groups.csail.mit.edu/medg/people/psz/Licklider.html; J.C.R. Licklider and Welden E. Clark, On-line man-computer communication, Proceedings of the May 1–3, 1962, Spring Joint Computer Conference, AFIPS JOINT COMPUTER CONFERENCES, at http://portal.acm.org/citation.cfm?id=1460847; J.C.R. Licklider and Robert W. Taylor, The Computer as a Communication Device, SCIENCE AND TECHNOLOGY 21-41 (April 1968), at http://www.utexas.edu/ogs/lectures/taylor/licklider-taylor.pdf. 6 Leonard Kleinrock, Information Flow in Large Communication Nets, RLE QUARTERLY PROGRESS REPORT (July 1961). 7 Barry M. Leiner, Vinton G. Cerf, David D. Clark, Robert E. Kahn, Leonard Kleinrock, Daniel C. Lynch, Jon Postel, Larry G. Roberts, Stephen Wolff, A Brief History of the Internet (3.32), (December 10, 2003) [hereafter “Leiner et al. (2003)”], at http://www.isoc.org/internet/history/brief.shtml. 1 Market Definition in Online Advertising systems was demonstrating the utility of broad based electronic communications between people. At this point in time the Internet was literally not open for business. The National Science Foundation (NSF) operated the Internet’s national-scale “Backbone” and enforced an “Acceptable Use Policy” (AUP) which prohibited usage for purposes “not in support of Research and Education.”8 Not until 1993, when the NSF reinterpreted the AUP, was the Internet fully opened to commercial traffic.9 B. The Importance of the World Wide Web, the GUI and the Browser The early-1990s Internet provided connections between sites, and individuals at various sites had information and resources that would be useful to others. But discovering and sharing that information was a daunting challenge. There was no easy or systematic way to uncover what information was available where or how to access it. Collections of information were balkanized, uncataloged and unindexed, and cloaked behind cryptic file names. Users maintained personal lists of what they had found, or learned of through word of mouth, in their imperfect views into the Internet.10 New information management systems such as Gopher and Wide Area Information Servers (WAIS) were created and were significant improvements—but fell short of what was needed.11 It was Tim Berners- Lee’s conception and development of the World Wide Web as a decentralized, scalable system of hypertext links that catalyzed the revolution that the Internet has become.12 Marc Andreessen and Eric Bina from the National Center for Supercomputing Applications (NCSA) at the University of Illinois released the Mosaic web browser in 1993—the first browser that allowed for the display of photographs and graphics positioned within a page of text. Andreessen cofounded Netscape in mid-1994, releasing what became the Mosaic Netscape (later, Netscape Navigator) browser for all major platforms on October 13, 1994.13 Millions of users took advantage of Netscape’s browser, which quickly grew to be the most popular browser in the market. C. Directories and Search Engines Increased the Value of the Web The development of the web and of browsers did not by itself solve an older problem: consumers could become aware of other sites on the Web only by word of mouth (e.g., sharing “hot lists”) or through recommendations from other sites (e.g., Cool Site of the Day). WebCrawler, launched in 1994, was perhaps the first search-engine service that embodied the three fundamentals we now expect: it was crawler based (to discover new sites), indexed, and able to search the full text (not just titles or summaries) of sites.14 There rapidly followed a proliferation of search engines, such as Lycos, Magellan, Excite, Infoseek, Inktomi, and AltaVista. Yahoo! took a different approach, using its “staff of experts” to categorize web sites into a hierarchical structure to build a directory around subject-based, demographic, and geographic content. In 1996, Stanford graduate students Larry Page and Sergey Brin began a research project that ultimately became a patented innovation in search and the beginnings of Google.15 Google remains the most-popular search site today. In September 2009, Americans conducted almost 14 millions searches. Almost 65% of these searches were conducted on Google’s sites. Yahoo had the second most popular search engine, 8 Leiner et al. (2003). 9 Worldwide Web Consortium (W3C), A Little History of the World Wide Web, at http://www.w3.org/History.html. 10 J.R. Okin, THE INFORMATION REVOLUTION: THE NOT-FOR-DUMMIES GUIDE TO THE HISTORY, TECHNOLOGY, AND USE OF THE INTERNET (Ironbound Press, 2005). 11 Neither Gopher nor WAIS used hypertext. WAIS connected only search engines together. Gopher’s prospects were damaged when the University of Minnesota announced it would charge a license fee for Gopher to certain classes of users. [Tim Berners- Lee and Mark Fischetti, WEAVING THE WEB 72-74 (HarperCollins 1999) (hereafter “Berners-Lee (1999)”].) 12 For the story of the development of the World Wide Web, see Berners-Lee (1999).