M.G. Siegler, I loved this post. I wanted to add a couple additional thoughts about why Echo is catching from my experiences over the last 6 months or so.
First, the Apple brand is now being stretched too far and that exposes gaps. The iPhone has always been a sensual touch experience that expanded to occupy our “lifeline” to the Internet. Siri competes with the core iPhone proposition and creates an inherent tension.
Echo, by contrast, is deceptively simple to the average consumer and only tries to do one thing: listen. This is why you can have 3-year-olds explaining and demonstrating Alexa to completely computer unsavvy folks.
And really, as painful as it is for fanboys (myself included), a company not really superb at design aesthetics, actually out Appled, Apple.