BTW, I would add that for me by far the most interesting part of the echo story is that it shows the unpredictability of trendlines in the space.
Prior to the echo’s release, Voice control was seen as something fairly frivolous with regards to home automation. The really expensive systems didn’t have it. There were people (including me) who needed it for physical reasons, but those systems were almost all designed around The idea of wearing a headset and using a dragon variation. General purpose voice control was available through Siri or Android, but again, you needed to have the microphone within about a foot of the speaker. The other standalone devices like Ubi just weren’t very good, and were seen more as toys.
You can see a lot of discussion about voice control options in one of the older forum threads:
Then came echo. With farfield recognition, a bunch of patents, A nine microphone 360° array, and a really astonishing farfield voice recognition technology at a price under $200, it was an absolute industry disruptor. Now voice was practical and affordable. And it worked really well for most people, including children, those who stuttered, those with a slight slur. Most people. It changed everything. So much so that a year later home automation systems that sell for $50,000 or more felt compelled to add Alexa compatibility. And builders that were offering HomeKit – enabled smart home packages were choosing devices that also worked with Alexa. Suddenly everyone was talking about voice control, from air-conditioner makers to Light switch designers. It was a huge paradigm shift for the whole industry.
Again, I don’t know if the echo itself will be the primary means of voice control for home automation in three or four years. It may not. But voice control will be part of almost all home automation systems moving forward, and that’s down to echo for sure. 
When voice control didn’t work very well, everyone was talking about intelligent automated routines that would dynamically change the state of devices without any intervention on the part of the resident. But once voice control technology improved to the point where it really does work, suddenly every manufacturer sees the advantages of it! A very interesting industry shift.