Online advertisements compete for consumer attention. This research investigates the effects of unexpected features in advertising such as motion and abrupt onset. The authors used a within-subject design to analyze the effects of three levels of advertising unexpectedness: high versus moderate versus low during both goal-oriented and free-browsing tasks. To that end, they recorded participant eye movements and measured the attitude toward the advertisement format and perceived intrusiveness. Results show that highly unexpected advertisements captured more attention in both tasks. Moreover, low and high levels of advertising unexpectedness attracted more attention in goal-oriented tasks and were associated with a more favorable attitude toward the advertisement and less perceived intrusiveness. The study further discussed theoretical and managerial implications of the findings.