This only works for those who still haven't used their Sonos Owners discount for $25.00 off an Amazon Echo Dot. I realized the discount ends tonight 11:59 PM PDT so luckily Amazon is running a 1 day sale of the echo dot as well.
The Echo Dot is reduced to $39.99, using the offer for Sonos Owners, you'll get the additional $25.00 off with a total price (before tax) $14.99. I just ordered a white echo dot for this price plus tax.
I post deals very rarely so I hope I did everything right. Sorry if I missed something, let me know. Unfortunately there's less than 2 hours left on this deal!