This study concentrates on the role of personal traits in technology acceptance by comparing which of the two personal trait constructs commonly used in IS research, personal innovativeness in the domain of information technology (PIIT) or technology readiness index (TRI), performs better in terms of promoting the explanatory power of the technology acceptance model (TAM). The comparisons are conducted in the case context of online services offered by electric suppliers, and the study is based on the data collected from 1,176 consumers through an online survey and analysed by using structural equation modelling (SEM). The findings of the study show that the inclusion of both PIIT and TRI into basic TAM promotes the explanatory power of the model especially in terms of perceived ease of use but also in terms of perceived usefulness and use intention. At the end of the paper, practical implications for electric suppliers and the adoption of their online services are also discussed.