"Pub/Sub is a unique and useful feature." Pub/sub exists in a multitude of different pieces of software. ZeroMQ has a pub/sub feature. PostgreSQL has the NOTIF

"Pub/Sub is a unique and useful feature." Pub/sub exists in a multitude of different pieces of software. ZeroMQ has a pub/sub feature. PostgreSQL has the NOTIFY/LISTEN command which is also a Pub/Sub channel allowing all those listening to be notified of certain events. This is by no means unique to Redis. It is very useful, so I'll agree with that!