The purpose of this study was to determine the effect of service quality,
promotion, and security on purchasing decisions. The sample selection in this
study used purposive sampling with the criteria: active students at the
Muhammadiyah University of purwokerto who have purchased products on
Tokopedia. Based on the criteria, there were 130 respondents who were selected
as the sample. The data analysis techniques used in this research were
descriptive statistical analysis, data instrument test, classical assumption test,
multiple linear regression analysis, hypothesis testing, and model fit test. The
results of the analysis showed that service quality, promotion and security
simultaneously affect purchasing decision. Service quality has a positive effect
on purchasing decision, promotion has a positive effect on purchasing decision,
and security has a significant and positive effect on purchasing decision.