1. A method comprising: receiving, by a user system that includes at least a processor system having at least one processor and a memory system and from a push service provider, a first push notification associated with a first priority level for display on the user system, the first push notification being a notification message that, from a publisher server, is pushed by the push service provider to the user system, the notification message being received at the user system without the user system sending a request to a publisher for the notification message; receiving by the user system, subsequent to receiving the first push notification, a second push notification associated with a second priority level for display on the user system; determining, by the user system, whether the second priority level is higher than a particular threshold priority level that is different from the first priority level; responsive to determining that the second priority level is higher than the particular threshold priority level, the user system: determining whether the second priority level is higher than the first priority level; and causing display of the second push notification prior to the first push notification when the second priority level is determined to be higher than the first priority level; and responsive to determining that the second priority level is not higher than the particular threshold priority level, the user system causing display of the first push notification prior to the second push notification level regardless of whether the second priority level is higher than the first priority level.