It utilizes hubbub push-notifications to deliver information about new videos in RSS format. It is unclear whether it requires the corresponding RSS feed to be

It utilizes hubbub push-notifications to deliver information about new videos in RSS format. It is unclear whether it requires the corresponding RSS feed to be operational. In any case, it just demonstrates the general approach: subscribe to a topic, and receive new events as soon as they happen without polling. The point is that it doesn't require much code: just glue together corresponding APIs.