Charles Zhechao Liu

Effects of Freemium Strategy in the Mobile App Market: An Empirical Study of Google Play

Abstract This paper examines the effect of the freemium strategy on Google Play, an online marketplace for Android mobile applications. By analyzing a large panel data set consisting of 711 ranked mobile apps, we found that the freemium strategy is positively associated with increased sales of the paid mobile apps. Positive trial experience as represented by high review rating of the free version of a mobile app leads to higher sales of its paid version, whereas high visibility of the free version of a mobile app as represented by its product rank does not have a significant impact on the sales of its paid version. This finding suggests that although offering a free trial version is a viable way to improve the visibility of a mobile app, offering a quality free app is more important in boosting sales of the paid app. Moreover, we found that the impact of review rating is reduced when the free version is offered, or when the mobile app is a hedonic app, because consumers have the ability to experience the app themselves before purchase. These findings extend understanding of the freemium business model to include a market characterized by simultaneous intramarket competition for both the freemium and paid products and demonstrate how such dynamics may influence sales of the paid products.

Rethinking FS-ISAC: An IT Security Information Sharing Network Model for the Financial Services Sector

This study examines a critical incentive alignment issue facing FS-ISAC (the information sharing alliance in the financial services industry). Failure to encourage members to share their IT security-related information has seriously undermined the founding rationale of FS-ISAC. Our analysis shows that many information sharing alliances’ membership policies are plagued with the incentive misalignment issue and may result in a “freeriding” or “no information sharing” equilibrium. To address this issue, we propose a new information sharing membership policy that incorporates an insurance option and show that the proposed policy can align members’ incentives and lead to a socially optimal outcome. Moreover, when a transfer payment mechanism is implemented, all member firms will be better off joining the insurance network. These results are demonstrated in a simulation in which IT security breach losses are compared both with and without participating in the proposed information sharing insurance plan.

Strategies for tomorrow's 'winners-take-some' digital goods markets

Markets characterized by multiple competing digital standards have room for more than one winner, unlike traditional analog markets.

Cracking Bitcoin wallets: I want what you have in the wallets

Abstract Bitcoin is increasingly popular, which is partly evidenced by the significant increase in its value in recent years. This increase in popularity and value has led to malicious actors stealing, or attempting to steal, Bitcoin wallet private keys in order to gain ownership of the digital currency held in these wallets. To demonstrate this security threat, two Bitcoin wallet software are studied, namely: Multibit HD and Electrum. Each wallet is subject to a combination of a password exploits and a restore wallet exploit. Findings suggest that it is possible to gain access to Multibit HD and Electrum wallets through offline brute force password attempts. Once a password is found, it is possible to restore a wallet with all Bitcoins contained within. This restoration is possible even if access to the Bitcoin wallet has never occurred. These findings highlight the need for more research into Bitcoin wallet security and forensics.

An Empirical Examination of an Agile Contingent Project/Method Fit Model

While research has demonstrated positive productivity and quality gains from using agile software development methods (SDMs), some experts argue that no single SDM suits every project context. We lack empirical evidence about the project contextual factors that influence when one should use these methods. Research suggests several factors to explain agile method appropriateness; however, generalizable empirical evidence supporting these suggestions is weak. To address this need, we used contingency theory and the information processing model to develop the agile contingent project/method fit model. Subsequently, we used the model to analyze the influence of project contextual factors and agile practices on software development professionals’ perceptions regarding agile SDM appropriateness. We tested the model using survey data collected from 122 systems development professionals who provided information regarding: 1) contextual factors surrounding a recent agile development project, 2) agile practices applied during the course of that project, and 3) perceptions regarding the relative fit (appropriateness) of the agile method used. Linear regression identified several significant relationships between project contextual factors, agile practices, and respondents’ relative fit perceptions.