The reason? Because neither play nice with Amazon's video service Prime Instant Video.
It's a bold decision that'll mean removing two of Amazon's best-selling products from its website and thus inevitably losing themselves some serious sales in the process.
This decision isn't actually that surprising though, Amazon's own competing product the Fire TV Stick has been hugely popular and while Amazon's reasoning is that neither Chromecast or Apple TV support Prime Instant Video very well, this move certainly won't harm Amazon's sale of its own products.
Barbara Kraus, an analyst at Parks Associates spoke to Bloomberg Business about the decision warning that while bold, this could come back to bite Amazon.
"This has the potential to hurt Amazon as much as it does Apple and Google, as a retailer, I want to give people a reason to come to me. When I take out best-selling brands, I take away those reasons."
The streaming market is huge, indeed Parks Associates estimates that there will be over 86 million streaming sticks and boxes by 2019.
Amazon, Google, Apple and Roku hold the major stakes in this industry, indeed Google confirmed at the launch of its new Chromecast that the previous model had sold over 20 million units.
Bloomberg's report features excerpts from an email by Amazon to its sellers saying: "Over the last three years, Prime Video has become an important part of Prime, it’s important that the streaming media players we sell interact well with Prime Video in order to avoid customer confusion."