I'm genuinely curious about how many of those "regular people" replaced a working thermostat with a Nest. Anecdotally, it certainly seems to me as if it's the geeky gadget types who get all excited about things like the Nest.

But the group of people within your anecdotal range is a heavily-skewed sample set.

Maybe. Certainly almost all of the people I associate with regularly could afford a Nest if they chose to do so. My experience is that most of the ones that I know who have actually done so are the same people who are always buying and trying out various types of gadgetry. I know lots of people who are technical to various degrees but aren't especially into electronic devices.

But wouldn't those people not able to program their current thermostat, for whatever reason, would have to be able to program their new fancier thermostat?

They don't scream this like they used to, but it's called the "Nest Learning Thermostat". There's one control, a ring that you turn left for colder and right for hotter. Over about a week the thermostat takes your inputs combined with the weather and develops a schedule it thinks you'll find comfortable. As it misses, you override it (again, just turn the ring) and Nest learns and updates its schedule for you.

You can use the app or the website to input a specific schedule if you prefer, which is still simpler than 99% of conventional thermostats.

Anecdotally I just programmed my grandmother's thermostat for her and it took me -- a 30-something with deep technical experience -- way too long to figure it out (I even had to break out the manual). What if grandma could just turn the ring left or right and the thermostat would come up with a schedule for her, wouldn't that be better?

But isn't that just a small part of the Nest idea?

Wouldn't the same thing be accomplished by getting someone to do it for them? Much like your grandmother and you? You set it up for her, she likely has to rarely deal with it again. All Nest does is take you out of the equation but you work for free.

Except the next time I visited, her thermostat had messed up its program and it was set at 80 degrees. Whether it was a power outage and dead backup battery, or she somehow fiddled with it and messed it up herself, it was once again in a broken state.

I hate to invoke the overused phrase, but the nest thermostat Just Works™.

Could not the same things happen with a Nest?

Not really, because it continually adjusts its schedule for you depending on your manual inputs, is powered by the HVAC wires themselves (and charges a small backup battery that you never have to worry about), and if you really wanted to you could log into her account and fix the thermostat remotely if somehow she managed to really break things. If all you do is turn the ring right or left for colder and hotter, it'll do its thing just fine.

You could hop into the menus and.. forget the wifi password or something I guess?

One thing nest handles really well is "I'm feeling a little too cold/hot tonight and I'm going to adjust the temp". You walk up and twist the ring and you're done. You don't have to disable scheduled mode or enable override mode or anything like that. Twist and done. I have a feeling that's how grandma messed up her thermostat, she was feeling cold so she turned it up to 80 (lol) and then the thermostat said, ok I guess this is my life now. 80 degrees forever.

I hate that this sounds like I'm arguing, because I'm not. I just find this discussion interesting.

If the device learns over time from grandma turning the dial up and down, does that not create strange data for the device to figure out? Take your example, grandma is cold so she turns the temp up; does this count as a manual input? Does that not eventually create a problem? Much like the original thermostat but takes longer?

Although, the account thing is interesting. Can you set the schedule and then disable the manual interface to let grandma change all she wants with no changes?

Heh, no offense taken.

I don't know the internals of how nest deals with wild swings in manual inputs, but I haven't seen a problem. Although even if it results in a "nights are 80 degrees" situation, the rest of the day is unaffected so at worst it's still better than the other thermostat.

Yes, you can set a schedule and disable the physical interface.

I'm not entirely sure what you're saying, but the whole point of the Nest thermostat is that it can still do a pretty good job without its owner having to do any programming.