Promotion plays an important role for the success of a product in the market and accounts for a large portion of the firm’s expenditure. This calls for judicious planning so that the promotion resources can be used efficiently at the same time creating maximum effectiveness. Firms use both mass and segment-driven promotion strategies to promote their product in a segmented market. Mass promotion spreads wider awareness of a product in the whole market with a spectrum effect while the segment-driven promotion is targeted to the distinct potential customers of the segments. This study proposes a mathematical model to determine the optimal length of a promotion campaign for a durable technology product, marketed in a segmented market under the joint effect of mass and segment-driven promotions. An application of the proposed model is demonstrated using real-life data. Differential evolution algorithm is used to solve the model.