It's not an unprecedented move, but it's a rare one for Amazon, which is staying in business with its two rivals for other products -- even tablets where iPad and Nexus devices compete with its Kindles. Even though Amazon is firing this shot, one could argue that the war was started by Apple and Google, since neither Chromecast nor Apple TV offers Amazon's Prime Video app.

That's a telling thing, because Amazon.com will still be selling Roku's streaming players, which control more market share than any other company, according to an August report by Parks Associates. The online retailer cited the lack of Prime Video as a reason for stopping sales of the two devices in an email it sent to sellers.

From the article "Here's How Much Amazon's Dis Will Cost Apple and Google" by Daniel B. Kline.