Santika, P.D. and Athar, H.S. 2026. The Effect of Digital Promotion, Online Advertising, and Customer Service Quality on the Decrease in Tokopedia Purchases Amid Competitive E-Commerce Competition in Mataram City. Indonesian Interdisciplinary Journal of Sharia Economics (IIJSE). 9, 2 (Aug. 2026), 17264-17273. DOI:https://doi.org/10.31538/iijse.v9i2.10635.