【Abstract】“Lookalike” products, including counterfeits and copycats, are increasingly common in today's global marketplace. Four lab experiments were conducted involving 653 participants, and data were analyzed through SPSS 26. Based on social representation (SR) theory and self-construal theory, this research examines how advertising for original brands impacts purchase intent for counterfeits and copycats differently. The results suggest that ads for the original product using value-expressive (vs. utilitarian) appeals result in lower intent to purchase copycat versions. However, ads for the original product using utilitarian (vs. value-expressive) appeals lead to lower purchase intent for counterfeit versions. The results also show that consumer need fulfillment mediates the interactive effect between ad appeal type and product type. The current research provides useful insights for marketers or retailers grappling with ongoing competitive threats posed by lookalike products and underscores the strategic utilization of various advertising tactics to reduce the demand for copycats and counterfeits.