Timely, constructive feedback on assessment is critically important to students and yet is increasingly difficult for time-poor academics to consistently provide. Marketing educators also face pressure to incorporate sustainability into both the curriculum and practices such as assessment. This article outlines the development of an innovative computer-based marking tool, SuperMarkIt (SMI), which promotes sustainability. Using an action research method, this article reports the results of the sixth cycle of review and improvement with data gathered from both educators and students. Results support the improvements in sustainability achieved by using SMI. Educationally, students report improved feedback quality in areas such as timeliness, legibility, constructiveness, personalization, and detail. Economically, academics report major increases in feedback quantity, and students report reductions in time and cost. Environmentally, SMI reduces reliance on paper as well as reducing travel required to submit and collect hard copy assessments. Continued development of SMI focuses on improving aspects related to technology adoption by educators. (Contains 2 figures and 2 tables.)