Large class teaching can be challenging, especially on highly complicated topics to be effectively delivered within 45-90 mins. Here, we adopted a well-known business approach called DAGMAR [“Defining advertising goals to measure advertising results” by Russell Colley] for teaching ~200 medical students on a highly complicated professional topic, “Pharmacogenomics” (MEDU2600) at CUHK. The core essence of DAGMAR is a highly connected communication axis of Awareness-Comprehension-Conviction-Action (ACCA). Often time, large classroom teachings for medical students focus on comprehension of knowledge mainly. Yet, with DAGMAR, communication activities (i.e. advertising) resulting in “buying actions” mean ultimate success. Similarly, designed teaching activities in a way that students “could and would action” is our ultimate teaching/communication goal. In a single lecture, we purposely adopted the ACCA elements of DAGMAR. We first sparked the “awareness” of the entire class by bringing them outside the classroom with a short documentary demonstrating the life-or-dead impacts of pharmacogenomics. This was immediately followed by “comprehension” (i.e. detailed scientific and medical information). “Conviction” was then built by showcasing world examples of pharmacogenomics, and related databases/resources (to convict them to act with solid knowledge). Finally, students’ “action” was drawn with one open question that inspired thinking and critical challenge of their learning to be applied to local settings. The approach was found appealing to students, not only reflected in satisfactory CTE comments, but also with students’ active discussions with family members. Subsequently, medical students became self-motivated to engage in deeper learning by initiating related medical virtual research lab talks outside classrooms.