Optimizing Your Online-Advertisement Asynchronously

We consider the problem of designing optimal online-ad investment strategies for a single advertiser, who invests at multiple sponsored search sites simultaneously, with the objective of maximizing his average revenue subject to the advertising budget constraint. A greedy online investment scheme is developed to achieve an average revenue that can be pushed to within $O(\epsilon)$ of the optimal, for any $\epsilon>0$, with a tradeoff that the temporal budget violation is $O(1/\epsilon)$. Different from many existing algorithms, our scheme allows the advertiser to \emph{asynchronously} update his investments on each search engine site, hence applies to systems where the timescales of action update intervals are heterogeneous for different sites. We also quantify the impact of inaccurate estimation of the system dynamics and show that the algorithm is robust against imperfect system knowledge

Supply Side Optimisation in Online Display Advertising

On the Internet there are publishers (the supply side) who provide free contents (e.g., news) and services (e.g., email) to attract users. Publishers get paid by selling ad displaying opportunities (i.e., impressions) to advertisers. Advertisers then sell products to users who are converted by ads. Better supply side revenue allows more free content and services to be created, thus, benefiting the entire online advertising ecosystem. This thesis addresses several optimisation problems for the supply side. When a publisher creates an ad-supported website, he needs to decide the percentage of ads first. The thesis reports a large-scale empirical study of Internet ad density over past seven years, then presents a model that includes many factors, especially the competition among similar publishers, and gives an optimal dynamic ad density that generates the maximum revenue over time. This study also unveils the tragedy of the commons in online advertising where users' attention has been overgrazed which results in a global sub-optimum. After deciding the ad density, the publisher retrieves ads from various sources, including contracts, ad networks, and ad exchanges. This forms an exploration-exploitation problem when ad sources are typically unknown before trail. This problem is modelled using Partially Observable Markov Decision Process (POMDP), and the exploration efficiency is increased by utilising the correlation of ads. The proposed method reports 23.4% better than the best performing baseline in the real-world data based experiments. Since some ad networks allow (or expect) an input of keywords, the thesis also presents an adaptive keyword extraction system using BM25F algorithm and the multi-armed bandits model. This system has been tested by a domain service provider in crowdsourcing based experiments. If the publisher selects a Real-Time Bidding (RTB) ad source, he can use reserve price to manipulate auctions for better payoff. This thesis proposes a simplified game model that considers the competition between seller and buyer to be one-shot instead of repeated and gives heuristics that can be easily implemented. The model has been evaluated in a production environment and reported 12.3% average increase of revenue. The documentation of a prototype system for reserve price optimisation is also presented in the appendix of the thesis

Online learning and decision-making from implicit feedback

This thesis focuses on designing learning and control algorithms for emerging resource allocation platforms like recommender systems, 5G wireless networks, and online marketplaces. These systems have an environment which is only partially known. Thus, the controllers need to make resource allocation decisions based on implicit feedback obtained from the environment based on past actions. The goal is to sequentially select actions using incremental feedback so as to optimize performance while simultaneously learning about the environment. We study three problems which exemplify this setting. The first is an inference problem which requires identification of sponsored content in recommender systems. Specifically, we ask if it is possible to detect the existence of sponsored content disguised as genuine recommendations using implicit feedback from a subset of users of the recommender system. The second problem is the design of scheduling algorithms for switch networks when the user-server link statistics are unknown (for e.g., in wireless networks, online marketplaces). The scheduling algorithm has to tradeoff between scheduling the optimal links and obtaining sufficient feedback about all the links for accurate estimates. We observe the close connection of this problem to the stochastic multi-armed bandit problem and analyze bandit-style explore-exploit algorithms for learning the statistical parameters while simultaneously assigning servers to users. The third is the joint problem of base station activation and rate allocation in an energy efficient wireless network when the channel statistics are unknown. The controller observes instantaneous channel rates of activated BSs, and thereby sequentially obtains implicit feedback about the channel. Here again, there is a tradeoff between learning the channel versus optimizing the operation cost based on estimated parameters. For each of these systems, we propose algorithms with provable asymptotic guarantees. These learning algorithms highlight the use of implicit feedback in online decision making and control.Electrical and Computer Engineerin

07471 Abstracts Collection -- Equilibrium Computation

From 18 to 23 November 2007, the Dagstuhl Seminar 07471 ``Equilibrium Computation\u27\u27 was held in the International Conference and Research Center (IBFI), Schloss Dagstuhl. During the seminar, several participants presented their current research, and ongoing work and open problems were discussed. Abstracts of the presentations given during the seminar as well as abstracts of seminar results and ideas are put together in this paper. The first section describes the seminar topics and goals in general. Links to extended abstracts or full papers are provided, if available

Entropy-Based Dynamic Ad Placement Algorithms for In-Video Advertising

With the evolution of the Internet and the increasing number of users over last years, online advertising has become one of the pillars models that sustains many of the Internet businesses. In this dissertation, we review the history of online advertising, will be made, as well as the state-of-the-art of the major scientific contributions in online advertising,in particularly in respect to in-video advertising. In in-video advertising, one of the major issues is to identify the best places for insertion of ads. In the literature, this problem is addressed in different ways. Some methods are designed for a specific genres of video, e.g., football or tennis, while others are independent of genre, trying to identify the meaningful video scenes (a set of continuous and related frames) where ads will be displayed. However, the vast majority of online videos in the Internet are not long enough to identify large scenes. So, in this dissertation we will address a new solution for advertisement insertion in online videos, a solution that can be utilized independently of the duration and genre of the video in question. When developing a solution for in-video advertising, a major challenge rests on the intrusiveness that the ad inserted will take upon the viewer. The intrusiveness is related to the place and timing used by the advertising to be inserted. For these reasons, the algorithm has to take in consideration the "where", "when" and "how" the advertisement should be inserted in the video, so that it is possible to reduce the intrusiveness of the ads to the viewer. In short, in addition to besides being independent of duration and genre, the proposed method for ad placement in video was developed taking in consideration the ad intrusiveness to the user.Com a evolução da Internet e o número crescente de utilizadores ao longo destes últimos anos, a publicidade on-line tornou-se um dos modelos base que tem sustentado muitos negócios na Internet. Da mesma forma, vídeos on-line constituem uma parte significativa do tráfego na Internet. É por isso possível entender desta forma, o potencial que ferramentas que possão explorar eficientemente ambas estas áreas possuem no mercado. Nesta dissertação será feita uma revisão da história da publicidade online, mas também será apresentado ao leitor uma revisão sobre o estado da arte das principais contribuições científicas para a publicidade on-line, em especial para a publicidade em video. Na publicidade em vídeo, uma das principais preocupações é identificar os melhores locais para a inserir os anúncios. Na literatura, este problema é abordado de diferentes maneiras, alguns criaram métodos para gêneros específicos de vídeo, por exemplo, futebol ou ténis, outros métodos são independentes do gênero, mas tentam identificar as cenas de vídeo (um conjunto contínuo de frames relacionadas) e apenas exibir anúncios neles. No entanto, a grande maioria dos vídeos on-line na Internet não são suficiente longos para serem identificadas cenas suficientemente longas para inserir os anúncios. Assim, nesta dissertação iremos abordar uma nova solução para a inserção de anúnicios em vídeos, uma solução que pode ser utilizada de forma independente da duração e gênero do vídeo em questão. Ao desenvolver uma solução para inserir anúncos em vídeos a grande preocupação recai sobre a intromissão que o anúncio inserido poderá ter sobre o utilizador. A intrusão está relacionada com o local e tempo utilizado pela publicidade quando é inserida. Por estas razões, o algoritmo tem que levar em consideração "onde", "quando" e "como" o anúncio deve ser inserido no vídeo, de modo que seja possível reduzir a intromissão dos anúncios para o utilizador. Em suma, para além de ser independente da duração e gênero do vídeo, o método proposto será também desenvolvido tendo em consideração a intromissáo do anúncio para o utilizador. Por fim, o método proposto será testado e comparado com outros métodos, de modo a que seja possivel perceber as suas capacidades

Optimizing trade-offs among stakeholders in real-time bidding by incorporating multimedia metrics

Displaying banner advertisements (in short, ads) on webpages has usually been discussed as an Internet economics topic where a publisher uses auction models to sell an online user's page view to advertisers and the one with the highest bid can have her ad displayed to the user. This is also called \emph{real-time bidding} (RTB) and the ad displaying process ensures that the publisher's benefit is maximized or there is an equilibrium in ad auctions. However, the benefits of the other two stakeholders -- the advertiser and the user -- have been rarely discussed. In this paper, we propose a two-stage computational framework that selects a banner ad based on the optimized trade-offs among all stakeholders. The first stage is still auction based and the second stage re-ranks ads by considering the benefits of all stakeholders. Our metric variables are: the publisher's revenue, the advertiser's utility, the ad memorability, the ad click-through rate (CTR), the contextual relevance, and the visual saliency. To the best of our knowledge, this is the first work that optimizes trade-offs among all stakeholders in RTB by incorporating multimedia metrics. An algorithm is also proposed to determine the optimal weights of the metric variables. We use both ad auction datasets and multimedia datasets to validate the proposed framework. Our experimental results show that the publisher can significantly improve the other stakeholders' benefits by slightly reducing her revenue in the short-term. In the long run, advertisers and users will be more engaged, the increased demand of advertising and the increased supply of page views can then boost the publisher's revenue