UPDATE (7:30am, Dec 12, 2017): Multi-room playback is now working on Echo's side. Just say - "Alexa, play Christmas Everywhere".
In August this year, Amazon rolled out a multi-room audio feature to its Echo devices, allowing users to simultaneously stream music across multiple speakers in their homes.
The feature basically lets you play audio from streaming services like Amazon Music, TuneIn, iHeartRadio and Pandora on multiple rooms when you have an Echo device installed.
Today, four months later when they first announced their multi-room audio feature, they quietly rolled out another update where you can finally have music playback on Spotify.
While listening to your favorite playlist, tap on "Device Available" where you can now see the Echo Speaker Group you created on your app, we named ours Everywhere. All you have to do is select it and it will automatically play your audio in all the Echo devices in the group.
At least from Spotify, you can already play and enjoy music on a group of Echos. But you still can't initiate the Spotify multi-room playback from Amazon Echo.
If you haven't created a Multi-Room Music group on your Alexa app yet, here's how: Select Smart Home > Select Groups > Create Groups > Select Multi-Room Music Group > Use pre-set group names from the drop-down or create your own with Custom Name > Select which devices to include and select Create Group.
Ready to play your favorite Spotify playlist?
Homestream Image from Amazon Website