Techniques are described for determining a priority order for generating, serving, or rendering components of content such as a web page. Behavioral data may be collected from user devices, the behavioral data describing user interactions with components of the content during previous presentations of the content on the user devices. Based on the behavioral data, a score may be determined for one or more of the components, the score based on component dwell times, component presentation frequency, or other information. A priority order for the components may be based on the determined scores, and the components may be generated, served, or rendered in the priority order.