The promotion is only available to Amazon Prime customers so if you don't already have a Prime membership you'll need to sign up for a free trial.
The Sonos PLAY:3 typically costs $299 but is now $255.84 (14% off). Sonos products don't go on sale very often so if you've had your eye on this speaker you may want to grab it before the sale ends.
Sonos recently expanded its lineup of wireless speakers with the PLAYBASE, a new speaker designed to sit underneath your TV. You can learn more about the PLAYBASE here.