In today’s digital age, digital marketing has become an integral part of our daily lives. The internet, mobile applications, social media and other digital communication tools have become ubiquitous and are used by billions of people worldwide. This study aimed to investigate the factors that affect consumer purchase decisions in digital marketing. A set of self-administered questionnaires has been distributed to 166 respondents in Malaysia. The stimulus-organism-response (SOR) theory was employed in this study. The independent variables included in this study are email marketing, social media marketing, mobile marketing, online advertising, influencer marketing and trust plays as a moderating variable in the study. The findings of this study revealed that five out of eleven hypotheses were supported. Trust significantly showed a mediation effect on the relationship between mobile advertising and online advertising on purchase decisions. These findings contribute to Sustainable Development Goal 9 (Industry, Innovation, and Infrastructure) by providing inputs on digital marketing’s effects, which can relate to the advancements in technology and innovation within the marketing sector. This research offers important insights for individuals, marketers and employers. Digital marketing is a powerful tool that can help businesses reach a larger audience, even with a limited budget. Utilising digital marketing tools like online advertising provides a valuable opportunity to strengthen online visibility, target the right audience, boost exposure and improve business outcomes.