Features are provided for facilitating prioritized transmission of content between content providers and content requesters. A content provider or intermediary entity obtains prioritization rules for transmitting network resources, such as resources embedded in or otherwise associated with web pages. The prioritization rules can be general rules applying to the transmission of all network resources or a large number thereof, or they can be customized for a specific network resource or small group thereof. The prioritization rules can be applied to the relative bandwidth utilization or data transfer rates of network resources. The relative bandwidth utilization or data transfer rates can be adjusted in response to network or user events.