`I Can't Even Buy Apples If I Don't Use Mobile Pay?': When Mobile Payments Become Infrastructural in China

Despite slow adoption in the West, mobile payments are the de facto solution for hundreds of millions of users in China for everything from paying bills to riding buses, from sending virtual ``Red Packets'' to buying money market funds. In this paper, we use the theoretical lens of infrastructure to study users' interactions with ubiquitous and embedded mobile payment systems in China, focusing on Alipay and WeChat Pay, the two dominant apps on the market. Based on data from a survey (n=466) and follow-up interviews (n=12) with users in China, we describe the diverse usage patterns across physical, social, and digital ubiquity, and a series of challenges people face. Reflecting on the lessons we learned from the Chinese case, in particular problems and pitfalls, we discuss some implications both for design and for policy. Our findings have important implications for other countries that have been moving towards greater adoption of mobile payments.