Government and non-government agencies have promoted mobile payment technology as an instrument of financial inclusion, with the agenda of fostering socioeconomic development. However, the true developmental capabilities of the technology can be recognized only by understanding its usage among the truly marginalized who are often ignored by mainstream studies. To address this issue, we develop a research model for the context of marginalized users, disadvantaged by low income and less education, distinguished from the general population by their habit of technology use, trust, perception of risk related to monetary transactions, and the network of users they transact with. To validate the model, we collect evidence using a survey of a low-income low-education sample of 98 respondents from the developing economy of India. The results show how habit and trust play a significant role compared to perceived risk, with an interesting interaction of education with network externalities. The findings hold major developmental implications related to mobile payment use by the marginalized, and hence their financial inclusion.