What is the opportunity for advertisers as search moves towards voice-based interaction?

The above is one that has been one of the key questions bubbling under the surface of the digital industry since the introduction of interfaces such as Apple’s Siri, etc, came on to the market.
With Amazon’s Alexa winning the lion’s share of the plaudits at this year’s Consumer Electronic’s Show (CES), and followed quickly by the likes of Google Home, etc, the urgency to resolve such a quandary is clear.
For instance, to copy and paste the current default mode