Internet search engines display advertisements along with search results, providing them with a major source of revenue. The display of ads is triggered by the use of keywords, which are found in the searches performed by search engine users. The fact that advertisers can buy a keyword that contains a trademark they do not own has caused controversy worldwide. To explore the actual effects of trademark and keyword advertising policies, we exploit a natural experiment in Europe. Following a decision by the Court of Justice of the European Union, Google relaxed its AdWords policy in continental Europe in September 2010. After the policy change, Google allowed advertisers to select a third party's trademark as a keyword to trigger the display of ads, with only a limited complaint procedure for trademark owners. We use click-stream data from European Internet users to explore the effect this policy change had on browsing behavior. Based on a dataset of 5.38 million website visits before and after the policy change, we find little average change. However, we present evidence that this lack of average effect stems from an aggregation of two opposing effects. While navigational searches are less likely to lead to the trademark owner's website, non-navigational searches are more likely to lead to the trademark owner's website after the policy change. The effect of changing keyword advertising policies varies with the purpose of the consumers using the trademark, and it is more pronounced for lesser-known trademarks. The article points to tradeoffs trademark policy is facing beyond consumer confusion. More generally, the article proposes a novel way how to analyze the effect of different allocations of property rights in intellectual property law.
1Electronic copy available at: http://ssrn.com/abstract=2266945
I IntroductionSince the commercialization of the Internet in the early 1990s, electronic communication networks have led to significant changes in value chains. Traditionally strong intermediaries -such as record companies, publishers, newspapers, or movie companies -have been struggling to define their future roles and find profitable business models in a radically changed environment of content consumption. At the same time, new intermediaries -such as search engines, auction sites, or social networks -have emerged. In some cases, they threaten to displace traditional intermediaries. In other cases, they complement them or create entirely new business models.In recent years, the discussion on intellectual property rules for intermediaries has increasingly focused on Internet search engines. In particular, a vigorous debate focuses on whether keyword-based advertising violates trademark law. In Google's version of the system -called Google AdWords -advertisers can buy advertising links in the 'sponsored links' section of a Google search results page. Thereby, advertisers purchase the possibility of having their ad displayed with the search results for a particular keyword that is relevant to their busines...