In Romania, the pandemic and post-pandemic effects, coupled with the nearly 80% increase in internet service penetration, have led to an extraordinary acceleration of e-commerce activity. Rising rents and operational costs, heightened financial challenges, and the improved quality and accessibility of internet connectivity have prompted some Romanian SMEs to sell their products and services online or through other online communication networks. In this context, it becomes essential to conduct marketing research to identify factors that could stimulate business performance. The purpose of this study is to assess the impact of e-marketing orientation, sustainability orientation, and technology orientation on the performance of online SMEs in Romania. Hypothesis testing and validation of the proposed construct model were conducted using structural equation modeling with partial least squares (SEM-PLS) and multi-group analysis (PLS-MGA). The research results have indicated that all three independent variables have positive and significant effects on online SMEs’ business performance. Finally, the study suggests that SME managers should focus on integrating these three variables and on selling products and services both nationally and internationally through the internet if they aim for long-term business performance growth.