Analysis of Spamdexing Influence and Click-Fraud Link-Spam in Online Marketing

The search engine advertising has become a dominant form of online advertising and is the predominant business model of search engines. The www leading search engine Google earned 16 billion US$ with search engine advertisement in the fiscal year 2007. The advertiser does not usually pay for the impression of the ad, but for a click on the advertisement. Fraudulent clicks present an inherent problem of this so called pay-per-click model. Click fraud represent any procedure that illegally exploits pay-per click markets. In particular, click fraud resolves around intentional clicks without intent to interact with the advertiser. In this context, a class action against several search engine providers in 2005 attracted attention (DELANEY 2005). To what extend, search engine providers are liable for the manipulation of clicks and click rates, was not finally judicially clarified. Google settled the class action by agreeing to pay its advertisers 90 billion US $. Click fraud represents a general threat for the pay-per-click model as well as a more specific threat for the business model of search engines. Search engine providers need to ascertain the reliability and correctness of the pay per-click model to preserve the trust of advertisers. Advertisers likewise need to consider click fraud in their decision process for the future configuration of advertising campaigns. In this contribution, we illustrate the main consequences of fraudulent clicks on frequently used measures of search engine advertising. Thereby, we support the early detection of and defense against click fraud in web.