Amazon SNS uses the
publish/subscribe model for delivery of messages. Recipients subscribe to one or more 'topics' within Amazon SNS. This may be hidden from the user as an internal part of a
mobile app. Receipt of a message may also be hidden from the user: this service is largely aimed at the internal processing of specific apps rather than as a generic email substitute. A game might receive bonus-level announcements or unlock keys for in-game purchases by this route. A ticket booking app could use it for confirmation vouchers, boarding passes or notifications of a delay to a flight. ==References==