Piggybacking off the Google Express thread via Target for a great use of this promo. $249 regular price minus promo code EXTRA25 drops it down to $186.75+tax and free shipping.
This is great considering the $170 nest3 with google mini deal doesn't come with a sensor (and the nest ones are expensive) and I missed the $160 ecobee3 +3 sensors costco deal but apparently the 4 has a lot more features like on board Alexa.
Also remember to take advantage of your local gas and electric rebates. In socal you can get $75 from each effectively making this really affordable for top of the line.