There have been several calls in the discipline of marketing to study marketing for a better world, and to increase the impact of marketing research. To address this, I examine the societal implications of marketing through three essays. Essay 1 focuses on how marketing strategy can be used to make the world a better place. Through a multi-year randomized controlled trial (RCT) field study in Malawi, I show how a marketing strategy intervention can be used to increase financial access for women in emerging markets thus attempting to address the United Nations Sustainability Development Goals (SDGs) #1, No Poverty, #5, Gender Equality, and #10, Reduced Inequalities. Essays 2 and 3 address the darker side of marketing. They use the opioid epidemic as a case study and examine the role of marketing in the negative societal outcome of the public health crisis. Essay 2 introduces the concept of marketing transgressions. It provides a descriptive overview of classic marketing strategies used by pharmaceutical companies and how they contributed to the opioid epidemic. A framework of strategic decisions that lead to responsible marketing or marketing transgressions is presented. Essay 3 builds upon essay 2 by examining the empirical link between marketing strategy and negative societal outcomes. Advertising and detailing spending in the opioid epidemic are linked to inappropriate prescriptions and subsequent overdose deaths, providing empirical support for the dark side of marketing strategy. This dissertation shows how marketing can be used to make the world a better place through increasing financial access for women, as well as how marketing strategy can result in marketing transgressions such as the opioid epidemic. By researching when marketing gets it right, and also when marketing gets it wrong, we can move towards a future of marketing for a better world.