That's exactly why Amazon sold you an echo. To buy stuff from them. Warming up the car and playing music are just little features to get you to put it into your home--they are not the main features. Please don't tell me this isn't obvious in 2018.
I got a amazon firestick recently. Installed Netguard on it (free android firewall) and pevented a few installed apps from phoning home. My firestick then refused to work. I left some of the apps disabled and my device is stuck in bootloop.
Now imagine the data they're collecting from their suite of amazon devices, where you can't control the data-mining.
It's not necessarily "to buy stuff from Amazon" I thought the direction was more meta than that - isn't it "to monitor the activities of people like you so that those activities can be influenced by people who pay for the data and/or analysis".
That could be look at what $politicalPartyAffiliates in your area consider important enough to change allegiance, so that a party that's marginal can present themselves as good for $socialGrouping in order to sway the vote. It's not necessarily just about purchasing.
It also allows analysis of other aspects of life, like, say, people who search for drug paraphenalia -- or a step further away, music that's associated [by someone] with people who take drugs -- which festivals are they going to this Summer ...
What determines “the main features”? The ones I listed certainly are the main ones for me. I’m sure Amazon wants me to use the ones that make them more money, but if I don’t....
Well, call it a good bet - I haven't ever bought anything with my Echo Dot, but the chances that I will, having it sitting there turning on the lights etc., are greater than if it wasn't sitting there.
You've still given away commercially useful information though that Amazon can trade - for example, the companies you're using for your lights and any other automation hardware. If that's associated with your Amazon account then companies can track you through the payment details and use that to target you with advertising in that podcast you paid for, or in the advert in your coffee company email you get when they wish you Happy New Year, or whatever.
That targetted selling may have no direct effect through the Echo itself, but the potential is there to increase the influence on you in other channels.
There may be other info, we have 3 kids who use our FireTV: I'd imagine they can estimate the child's age & sex and give targetted advertising in emails/web pages to companies selling toys for those ages. Based on the apps (whatever they call them, skills?), they can probably target that much better.
