Web 3.0 promises a more decentralized and valuable Internet by allowing users to truly own and control their data. This is in contrast to Web 2.0, where users and their generated data and traffic have been centralized by several major Internet platforms. In this article, we investigate the design of Web 3.0 platforms through a case study. Specifically, we propose a platform targeting the long-tail market comprising customized products. To handle the decentralized user demands, we realize the concept of virtual enterprise (VE) on the platform, such that different users can cooperate through running specific VEs with predefined workflows, thus greatly reducing the transaction costs. Furthermore, we develop the micro-blockchain protocol, allowing users to store consistent copies of transaction data on their own devices. Unlike existing coin-based blockchains, micro-blockchain does not require global consensus, hence it can naturally scale with more concurrent transactions. Moreover, a data-driven trust model is utilized, so that users can evaluate their trust relationship with others solely based on the data of their past activities, instead of requiring the help of a centralized trust authority, which is usually acted by the platform. At last, we point out the key issues on designing general Web 3.0 applications.