I never tire of telling people how bad my Nest Protect smoke alarm is. It is a buggy box which requires magic batteries and doesn't support some of its advertised features. Still, I've drilled it on to my ceiling now, so have to put up with it.
This morning, I glanced bleary-eyed at my phone.
OH FUCK! THE HOUSE IS ON FUCKING FIRE AND MY FUCKING NEST ISN'T WORKING!
I sniffed the air. I couldn't smell anything strange. Perhaps it is deadly Carbon Monoxide.
I frantically clicked the email to see if I was about to be incinerated or gassed to death.
Oh. It's a marketing email. Nest wants me to buy another of their crappy products.
Now, perhaps I should have been more alert - but when I see an email which says "Nest. Smoke Alarm. Critical. Only if working" my first thought isn't "Golly! I sure could do with a few more smoke alarms!" My first thought, genuinely, was that there was an emergency.
To say that I'm upset with Nest is an understatement. The company has a troubled history with their products and their repeated inability to deliver a competent experience is leading me to junk their smoke alarm.
If you are making domestic IoT devices, remember you are being invited into someone's home. You are a guest and must behave with respect. To send a deliberately sensationalist email in the early morning is a gross breach of trust.