It seems like they would want Alexa on every platform, so owning a platform (other than the Echo, which they needed to launch it) may not be advantageous. Though you might say the same for the Kindle, and that didn't stop them from making their own.
You'd think so, but Amazon doesn't think that way. They don't sell chromecasts or Apple TV's in their store, when they'd make far more money selling them and getting buyers to subscribe to Amazon Video...
Is there a confirmed analysis of this? Just curious because I'm sure Amazon probably has an army of excel analyst warlocks (and chief warlocks) + a board to answer to...