US Patent 9979796 Efficient pre-fetching notifications

A method includes sending to a user device prefetch notifications, which notify the user device of available prefetch updates. Requests are received from the user device for one or more first prefetch updates, selected by the user device in response to the prefetch notifications. Selected prefetch updates are delivered to the user device, including both (i) one or more of the requested first prefetch updates, and (ii) one or more second prefetch updates selected from among the available prefetch updates not in response to any request from the user device.