This research was conducted to find out on how the effect of customer engagement on online sales from the perspective of customers who purchase virtual goods in the online mobile game Free Fire. The research was carried out by involving 200 online Free Fire mobile game players. Data collection was done by distributing a questionnaire containing 37 questions with a 1-7 Likert Scale based on the judgmental sampling method. Data were analyzed by the SEM method based on PLS.This study looks at antecedent variables that shape customer engagement in the form of game satisfaction, game customization, and social interaction. The results of this study prove that there is a significant positive relationship from game satisfaction and social interaction to psychological engagement, psychological engagement to behavioral engagement, and behavioral engagement has a significant positive relationship with the amount of money spent on virtual goods purchases in games. While for game customization does not have a significant effect on psychological engagement, and psychological engagement does not have a significant effect on the amount of money spent in purchasing virtual goods in games. The results of this study are expected to be taken into consideration for relevant decision making for game developer companies to increase customer engagement in their marketing strategies for mobile online games they make. / Tujuan penelitian ini dilakukan untuk menguji bagaimana pengaruh customer engagement terhadap penjualan online dari sisi perspektif customer yang melakukan pembelian virtual goods dalam mobile onlie game Free Fire. Penelitian dilakukan dengan melibatkan 200 pemain mobile game online Free Fire. Pengumpulan data dilakukan dengan menyebarkan kuesioner berisi 37 pertanyaan dengan Skala Likert 1 – 7 berdasarkan metode judgemental sampling. Data dianalisis dengan metode SEM berbasiskan PLS. Penelitian ini melihat variabel – variabel anteseden yang membentuk customer engagement yang berupa game satisfaction, game customization, dan social interaction. Dari hasil penelitian ini dibuktikan adanya hubungan positif signifikan dari game satisfaction dan social interaction terhadap psychological engagement, psychological engagement terhadap behavioral engagement, dan behavioral engagement memiliki hubungan yang poositif signifikan dengan jumlah uang yang dibelanjakan dalam pembelian virtual goods dalam game. Sementara untuk game customization tidak berpengaruh signifikan terhadap psychological engagement, dan psychological engagement tidak memiliki pengaruh signifikan dalam jumlah uang yang dibelanjakan dalam pembelian virtual goods dalam game Hasil dari penelitian ini diharapkan dapat dijadikan bahan pertimbangan untuk pengambilan keputusan relevan bagi perusahaan developer game untuk meningkatkan customer engagement dalam memasarkan mobile online game yang mereka buat.