adPerf: Characterizing the Performance of Third-party Ads

Monetizing websites and web apps through online advertising is widespread in the web ecosystem. The online advertising ecosystem nowadays forces publishers to integrate ads from these third-party domains. On the one hand, this raises several privacy and security concerns that are actively studied in recent years. On the other hand, given the ability of today's browsers to load dynamic web pages with complex animations and Javascript, online advertising has also transformed and can have a significant impact on webpage performance. The performance cost of online ads is critical since it eventually impacts user satisfaction as well as their Internet bill and device energy consumption. In this paper, we apply an in-depth and first-of-a-kind performance evaluation of web ads. Unlike prior efforts that rely primarily on adblockers, we perform a fine-grained analysis on the web browser's page loading process to demystify the performance cost of web ads. We aim to characterize the cost by every component of an ad, so the publisher, ad syndicate, and advertiser can improve the ad's performance with detailed guidance. For this purpose, we develop an infrastructure, adPerf, for the Chrome browser that classifies page loading workloads into ad-related and main-content at the granularity of browser activities (such as Javascript and Layout). Our evaluations show that online advertising entails more than 15% of browser page loading workload and approximately 88% of that is spent on JavaScript. We also track the sources and delivery chain of web ads and analyze performance considering the origin of the ad contents. We observe that 2 of the well-known third-party ad domains contribute to 35% of the ads performance cost and surprisingly, top news websites implicitly include unknown third-party ads which in some cases build up to more than 37% of the ads performance cost

Investigating the Impact of the Blogsphere: Using PageRank to Determine the Distribution of Attention

Much has been written in recent years about the blogosphere and its impact on political, educational and scientific debates. Lately the issue has received significant attention from the industry. As the blogosphere continues to grow, even doubling its size every six months, this paper investigates its apparent impact on the overall Web itself. We use the popular Google PageRank algorithm which employs a model of Web used to measure the distribution of user attention across sites in the blogosphere. The paper is based on an analysis of the PageRank distribution for 8.8 million blogs in 2005 and 2006. This paper addresses the following key questions: How is PageRank distributed across the blogosphere? Does it indicate the existence of measurable, visible effects of blogs on the overall mediasphere? Can we compare the distribution of attention to blogs as characterised by the PageRank with the situation for other forms of Web content? Has there been a growth in the impact of the blogosphere on the Web over the two years analysed here? Finally, it will also be necessary to examine the limitations of a PageRank-centred approach

OPENING THE SOCIAL MEDIA BLACK BOX - A FEATURE-BASED APPROACH

In this study we analysed 25 social media tools that have a significant penetration in the market, and defined a comprehensive list of features related to social media technologies. Using a grounded approach, we conducted a cluster analyses to organize tools and their features into categories. Groups of tools that share similar capabilities emerged from the data. Finally, we identified similarities in features among tools in the same cluster. The result is a feature-based classification of the social media tools that are available in the market. The paper proposes a set of research questions intended to guide future studies related to social media features within the organization

Social networking websites: who survives?

This article studies the relationship between the characteristics of social networking sites (SNSs) and their probability of survival. The data sample includes 224 SNSs launched throughout the world from 1995 to 2015 and that can be described by focus strategy, business financing methods and interactions with external companies, such as partnerships, mergers and acquisitions. Three factors are systematically associated with closure hazard rates. First, compared with SNSs that address a specialized audience, generalist SNSs have a three times higher probability of closing. Second, being the target of a merger or acquisition more than doubles the probability of closure. Third, new entrants have higher probability to survive if compared with SNSs with experience in the industry

RSS Feeds, Browsing and End-User Engagement

Despite the vast amount of research that has been devoted separately to the topics of browsing and Really Simple Syndication (RSS) aggregation architecture, little is known about how end-users engage with RSS feeds and how they browse while using a feed aggregate. This study explores the browsing behaviors end-users exhibit when using RSS and Atom feeds. The researcher analyzed end-users’ browsing experiences and discusses browsing variations. The researcher observed, tested, and interviewed eighteen (N=18) undergraduate students at the University of Tennessee to determine how end-users engage with RSS feeds. This study evaluates browsing using two variations of tasks, (1) an implicit task with no final goal and (2) an explicit task with a final goal. The researcher observed the participants complete the two tasks and conducted exit interviews, which addressed the end-users’ experiences with Google Reader and provided further explanation of browsing behaviors. The researcher analyzed the browsing behaviors based upon Bates’ (2007) definitions and characteristics of browsing. The results of this exploratory research provide insights into end-user interaction with RSS feeds

Inside the Philanthropic Venture Capital Investment Model: An exploratory comparative Study

Aquesta tesi doctoral és el primer estudio exploratori sobre el procés d'inversió dels inversors de capital risc filantròpic en empreses socials. El model, des del punt de vista del finançador, uneix els principis del model tradicional de capital risc amb objectius socials. A través de la provisió de capital i de serveis no-financers a empreses socials, el capital risc filantròpic dóna suport a les necessitats de sostenibilitat de les empreses en què inverteix amb l'objectiu d'afavorir els seus creixement i en últim maximitzar els seus impacte social. La hipòtesis bàsica del capital risc filantròpic és que els fons filantròpics han de ser dirigits a problemes socials importants per la qual cosa els finançadors han de esforçar-se de maximitzar l'impacta del seu finançament donant compte dels resultats a les parts interessades. Els inversors de capital risc filantròpic creuen que la sostenibilitat econòmic- financera de les empreses socials participades pugui ser l'enllaç entre creixement i maximització de l'impacta social: només si aquestes empreses són capaços de ser independents des del punt de vista econòmic, poden enfocar en el seu missió social i per tant maximitzar el seu impacte. De tota manera, la value proposition del model de capital risc filantròpic és fortament diferent de la del capital risc tradicional ja que el primer té l'objectiu de maximitzar l'impacta social, i el segon el rendiment financer de la inversió aquesta. És així clau entendre com les tècniques i l'estructura del procés d'inversió del capital risc es pugui adaptada en el cas del capital risc filantròpic. Basant-se en la teoria de les asimetries informatives i utilitzant una metodologia de recerca articulada en dos passos, aquesta recerca contribueix a la literatura existent de capital risc i emprenedoria social mostrant com problemes de selecciona adversa són gestionats en la fase de deal flow i selecció. A més, s'analitza també la manera com problemes de moral hazard impacten en la fase d'estructuració de la inversió i en la seva fase de post-investment. Els resultats indiquen que les inversions de capital risc filantròpic estan efectivament caracteritzades per un alt nivell de selecciona adversa que es gestiona amb una recerca proactiva de noves inversions i tenint en compte sobretot el factor humà. Al contrari, el moral hazard d'unes qüestió marginal en les fases de deal structuring i post-investment, amb els inversors que es aporten més com stewards de les empreses finançades que com a principals.Esta tesis doctoral es el primer estudio exploratorio sobre el proceso de inversión del capital riesgo filantrópico en empresas sociales. El modelo, desde el punto de vista del financiador, une los principios del modelo tradicional de capital riesgo con objetivos sociales. A través de la provisión de capital y de servicios no-financieros a empresas sociales, el capital riego filantrópico apoya las necesidades de sostenibilidad de las empresas en que invierte, con el objetivo de favorecer su crecimiento y como último objetivo maximizar su impacto social. La hipótesis básica del capital riesgo filantrópico es, que los fondos filantrópicos deben ser dirigidos a problemas sociales importantes por lo cual los financiadores tienen que esforzarse en maximizar el impacto de su financiación dando cuenta de los resultados a las partes interesadas. Los inversores de capital riesgo filantrópico creen que la sostenibilidad económico-financiera de las empresas sociales participadas puede ser el enlace entre crecimiento y maximización del impacto social: solo si estas empresas son capaces de ser independientes desde el punto de vista económico, pueden enfocarse en su misión social y por lo tanto maximizar su impacto. De todas formas, la value proposition del modelo de capital riesgo filantrópico es considerablemente distinta de la del capital riesgo tradicional ya que el primero tiene el objetivo de maximizar el impacto social, y el segundo el rendimiento financiero de la inversión misma. Es así clave entender como las técnicas y la estructura del proceso de inversión del capital riesgo se pueda adaptar en el caso del capital riesgo filantrópico. Basándose en la teoría de las asimetrías informativas y usando una metodología de análisis articulada en dos pasos, esta investigación contribuye a la literatura existente de capital riesgo y de iniciativas emprendedoras sociales demostrando, como problemas de selección adversa son gestionados en la fase de deal flow y selección de las inversiones. Además, se analiza también la manera en que problemas de comportamientos oportunistas impactan en la fase de estructuración de la inversión y en su fase de post-investment. Los resultados indican que las inversiones de capital riesgo filantrópico están efectivamente caracterizadas por un alto nivel de selección adversa que se gestiona con una búsqueda proactiva de nuevas inversiones y teniendo en cuenta sobre todo el factor humano. Al contrario, el problema de comportamientos oportunistas resulta ser una cuestión marginal en las fases de estructuración de la inversión y de post-investment, con los inversores que actúan mas como stewards de las empresas financiadas que como principales.This dissertation is a first exploratory study on philanthropic venture capital, a new and particular financing form available for social entrepreneurs that unites the profit-seeking investment principles characterizing the traditional venture capital investment model with social aims. The provision of capital and non-financial services to social enterprises are considered of key importance towards the maximizations of social impact as both elements are needs to enable social enterprises in becoming self-financially sustainable and thus able to successfully play in the marketplace. The main assumption underlying the philanthropic venture capital's value proposition is that size matters: funding growing social organizations is a sign of social success and relevance. The basic commitments are grounded in the belief that philanthropic funds need to be applied to important social problems and that funders must strive to maximize the social impact of their investment and only through growth the aim can be achieved. Philanthropic venture capitalists believe sustainability can be the link between growth and social impact maximization: if social enterprises are able to become self-financially sufficient, they can focus on their social mission. However, since the value proposition of the venture capital and philanthropic venture capital investment models are different, the key issue is understanding how the practices used in the former are modified by the latter. Grounded in an asymmetric information and stewardship theory framework and using a two step research design, I build on and contribute to previous work on venture capital and social entrepreneurship showing how adverse selection is mitigated in the deal flow and selection stages of the investment model. In addition to this, I also analyze how moral hazard issues shape the deal structuring and post-investment phases. Results indicate that philanthropic venture capital investments are indeed characterized by adverse selection which is managed through a proactive search of new deals which are then selected based on the human capital of the social entrepreneur. On the contrary, moral hazard tends to be a marginal issue in the deal structuring and post-investment phased of the investment, with investors acting as stewards of the organizations they back rather than principals