Although customer engagement has been deemed critical for optimizing social media marketing performance, prior research has mainly examined customer engagement through cross‐sectional designs, thus limiting insight into its evolving dynamics over time. To address this gap, we adopt uses‐and‐gratifications theory to explore the associations among customers' evaluations of a firm's social media marketing activities, customer engagement, and customer stickiness on a brand's social media page at three points in the post‐purchase stage of the consumption journey. Cross‐lagged autoregressive panel model analyses suggest that, first, customers' evaluations of firms' social media marketing activities, customer engagement, and customer stickiness fluctuate. Second, customer engagement has cross‐lagged longitudinal effects on stickiness over time; the same applies to the role of stickiness in customers' evaluations of the firm's social media marketing activities. However, no cross‐lagged effects arise from (a) firm‐based social media marketing activities to customer stickiness or (b) stickiness to engagement. These findings contribute to the customer engagement literature by describing the dynamics of such engagement and its interrelationships with other key constructs across time.