Thesis (M. Journ.)--University of Hong Kong, 2001. / Includes bibliographical references (leaves 60-73).

Thesis (Ph. D.)--University of Texas at Austin, 2002. / Vita. Includes bibliographical references. Available also from UMI Company.

Source: Masters Abstracts International, Volume: 47-06, page: 3556. Adviser: Paul Rowan. Includes bibliographical references.

Thesis (Ph. D.)--University of Washington, 2003. / Vita. Includes bibliographical references (leaves 105-111).

Thesis (M.S.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains iii, 49 p. Includes two sample banner ads: one animated and one content-specific. Vita. Includes abstract. Includes bibliographical references (p. 34-37).

Advances in information technology have created radically new business models, most notably the integration of advertising with keyword-based targeting, or "keyword advertising." Keyword advertising has two main variations: advertising based on keywords employed by users in search engines, often known as "sponsored links," and advertising based on keywords embedded in the content users view, often known as "contextual advertising." Keyword advertising providers such as Google and Yahoo! use auctions to allocate advertising slots. This dissertation examines the design of keyword auctions. It consists of three essays. The first essay "Ex-Ante Information and the Design of Keyword Auctions" focuses on how to incorporate available information into auction design. In our keyword auction model, advertisers bid their willingness-to-pay per click on their advertisements, and the advertising provider can weigh advertisers' bids differently and require different minimum bids based on advertisers' click-generating potential. We study the impact and design of such weighting schemes and minimum-bids policies. We find that weighting scheme determines how advertisers with different click-generating potential match in equilibrium. Minimum bids exclude low-valuation advertisers and at the same time may distort the equilibrium matching. The efficient design of keyword auctions requires weighting advertisers' bids by their expected click-through-rates, and requires the same minimum weighted bids. The revenue-maximizing weighting scheme may or may not favor advertisers with low click-generating potential. The revenue-maximizing minimum-bid policy differs from those prescribed in the standard auction design literature. Keyword auctions that employ the revenue-maximizing weighting scheme and differentiated minimum bid policy can generate higher revenue than standard fixed-payment auctions. The dynamics of bidders' performance is examined in the second essay, "Keyword Auctions, Unit-price Contracts, and the Role of Commitment." We extend earlier static models by allowing bidders with lower performance levels to improve their performance at a certain cost. We examine the impact of the weighting scheme on overall bidder performance, the auction efficiency, and the auctioneer's revenue, and derive the revenue-maximizing and efficient policy accordingly. Moreover, the possible upgrade in bidders' performance levels gives the auctioneer an incentive to modify the auction rules over time, as is confirmed by the practice of Yahoo! And Google. We thus compare the auctioneer's revenue-maximizing policies when she is fully committed to the auction rule and when not, and show that she should give less preferential treatment to low-performance advertisers when she is fully committed. In the third essay, "How to Slice the Pie? Optimal Share Structure Design in Keyword Auctions," we study the design of share structures in keyword auctions. Auctions for keyword advertising resources can be viewed as share auctions in which the highest bidder gets the largest share, the second highest bidder gets the second largest share, and so on. A share structure problem arises in such a setting regarding how much resources to set aside for the highest bidder, for the second highest bidder, etc. We address this problem under a general specification and derive implications on how the optimal share structure should change with bidders' price elasticity of demand for exposure, their valuation distribution, total resources, and minimum bids. / text

published_or_final_version / Business / Doctoral / Doctor of Philosophy

Overlay routing has been successful as an incremental method to improve the current Internet routing by allowing users to select the Internet paths by themselves. By its nature, overlay routing has selfish behavior, which makes impact on the related components of the Internet routing. In this thesis, we study three interactions related to overlay routing. First, overlay routing changes the traffic patterns observed by the network operating side, which uses traffic engineering techniques to cope with the dynamic traffic demands. We improve this vertical interaction between overlay routing and traffic engineering. Secondly, the performance of overlay routing may be affected by the action of other coexisting overlays. An initial result on the horizontal interaction among multiple overlays is given. Lastly, within a single overlay network, overlay nodes can be regarded as independent decision makers, who act strategically to maximize individual gain. We design an incentive-based framework to achieve Pareto-optimality in the internal interaction of overlay routing.

Not available / text

The purpose of this paper is to increase knowledge and understanding of how an identity is constructed on the internet and if it is different from the everyday identity. To analyze this, I have studied the theories of how identity is constructed in everyday life and then applied this on the empirical data that I have collected. In this study, I have chosen to pursue a qualitative approach using semi-structured interviews to gather the empirical data. In the study, six informants participated and all of them has an active social life both on and off the internet. The results that I have found in this study shows that an identity online is constructed in a similar way as it does in real life, however, some limitations that exist in everyday life do not exist online. In the study, I have also concluded that annonymiteten on the Internet can have both negative and positive effects on the construction of an identity. Of the empirical evidence I have gathered has shown that individuals can both use the anonymity that the internet provides to increase their confidence in social interactions. The empirical material have also shown that the same anonymity can make people behave in undesirable ways that they would in everyday life would never do.