Adversarial Information Retrieval Aspects of Sponsored Search

1. Adversarial Information Retrieval Aspects of Sponsored Search Jim Jansen College of Information Sciences and Technology The Pennsylvania State University jjansen@ist.psu.edu

2. Agenda • What is sponsored search? • How does sponsored search work? • Adversarial IR aspects – click fraud • How does click fraud work? • Click fraud prevention (or at least mitigation) • Conclusion

3. Sponsored Search • is an increasingly important, popular, and uniquely contextual form of information interaction on the Web. • adversarial techniques to subvert sponsored search have received little attention in the research community. • the negative effect of spam on the sponsored search process may have greater implications than on the algorithmic process.

4. Sponsored Search • content providers pay Web search engines to display specific links in response to user queries alongside the algorithmic. • is increasingly important in locating information on the Web. • a distinctive form of IR - uniquely dynamic contextual relationship. • significant social and political repercussions if the process is significantly compromised. Fain, D. C. and Pedersen, J. O., Sponsored Search: A Brief History, Bulletin of the American Society for Information Science and Technology, vol. 32, pp. 12-13, 2006

5. Sponsored Search – Goals and Processes Process • Provider Content • Provider Bid • Search Engine Review Process • Search Engine Keyword and Content Index • Search Engine User Interface • Search Engine Tracking • Searcher 5 1 4 7 3 2 6

6. Sponsored Search – Goals and Processes Goals • Searcher – find right information, site, or service with the right characteristics at the right time • Search Engine – service relevant content • Provider – infer searcher intent or affect searcher attitude 3 2 1

7. Adversarial Aspects • Sponsored search significantly reduces spam. • Why? The cost motive for the provider and search engine to present relevant content. • Search engines have review processes consisting of both automated and manual aspects to help ensure this. • Monetary factors significantly reduce spam content.

8. Adversarial Aspects • There is the issue of click fraud with sponsored search. • Click fraud is the intentional clicking on a sponsored link where the perpetrator does not intend to buy (or use) the products or services advertised. • Click fraud has not been widely perceived as search engine spamming, but its negative effect is severe.

9. Click Fraud • can take various forms, but the final result is usually the same. • Content providers pay for unproductive traffic. • produces revenue for the major search engines and Web sites. • the clicks generate sales commissions based on the content provider’s bid even if the click does not result in a sale.

10. Adversarial Aspects • content providers are contractual obligated to pay for all valid clicks. • the search engine company has discretion over what is valid. • sponsored search programs suffered a click fraud rate of 12%, translating to more than $1.5 billion of Google's ad revenue in 2005. • some content providers complain that their individual click fraud rate is as high as 35%. Liedtke, M., Click Fraud Concerns Hound Google, in ABC News Money, 2006 http://abcnews.go.com/Technology/wireStory?id=1934655&CMP=OTC-RSSFeeds0312

11. Click Fraud Implementation An Example of Click Fraud on the Sponsored Listings of a Web Search Engine.

12. Click Fraud Implementation An Example of Contextual Link Where Click Fraud Can Occur

13. Click Fraud Implementation A Sponsored Link Concerning Google’s AdSense Program

14. Click Fraud Prevention • Automated and Human Filters: employ both automated and human filters in an attempt to identify current and prevent future click fraud. • Pay-per-action Paradigm: a shift in paradigm from pay-per-click to pay-per-action (i.e., actually executes an action, such as purchasing a product). • Block Blacklisted IP addresses: IPs that are know spammer sites. Click fraud perpetrators also use these IPs.

15. Click Fraud Prevention • Aggressive monitoring of click fraud perpetrators: Click fraud is similar to what occurred in the online music industry. • The Recording Industry Association of America’s (RIAA) campaign against illegal files sharing via peer-to-peer networks. • Search engine’s must make efforts to ensure trust: Trust is a, if not the, critical element in the sponsored search paradigm. • Whether through independent auditing or internal efforts, content providers and searchers must have trust in the process if it is to be a long term business model.

16. Conclusion • View of sponsored search as “solely advertising” may be incorrect. • From the searcher’s point of view, sponsored links are just another type of search engine result. • Sponsored search model will have increasing impact as new players enter the field (i.e., Microsoft Research and AskJeeves) and second tier players (i.e., FindWhat, Kanoodle)

17. Conclusion • Major search engines continue to transform the basic sponsored search model. • Cross-medium linkage can significantly increase the synchronization of information pull-and-push, perhaps providing more relevant content to the searcher. • Click fraud threatens the entire process. With rates between 12% and 16%, translates into billions of dollars per year, and it jeopardizes the entire model as it decreases trust in the system.

18. Applicable References(Available at http://ist.psu.edu/faculty_pages/jjansen/) • Jansen, B. J. and Resnick, M. Forthcoming. An examination of searcher's perceptions of non-sponsored and sponsored links during ecommerce Web searching. Journal of the American Society for Information Science and Technology. • Jansen, B. J. 2006. Paid search. IEEE Computer. 39(7), 88-90. • Jansen, B. J. and Molina, P. 2006. The effectiveness of Web search engines for retrieving relevant ecommerce links. Information Processing & Management. 42(4), 1075-1098. • Jansen, B. J. 2006. Paid Search as an Information Seeking Paradigm. Bulletin of the American Society for Information Science and Technology. 32(2), 7-8. • Jansen, B. J. and Resnick, M. 2005. Examining Searcher Perceptions of and Interactions with Sponsored Results. Workshop on Sponsored Search Auctions, The Sixth ACM Conference on Electronic Commerce (EC'05). Vancouver, Canada. 5-8 June.

19. CFP - International Journal of Electronic Business (IJEB) • Special issue on Sponsored Search (Due date: 15 February 2007) • Guest Editors • Jim Jansen, The Pennsylvania State University • Abdur Chowdhury, AOL and the Illinois Institute of Technology.

20. Questions and Discussion Jim Jansen College of Information Sciences and Technology The Pennsylvania State University jjansen@ist.psu.edu