It's really cool device, especially the voice search, but my cell phone + chrome-cast is more than adequate for me right now for streaming content. I don't really see the need for games on it, but that's just me. Prime members getting a discount would be a very inciting offer since you have to pay for prime too to get access to content.
Be sure to checkout Amazon FaceTime, it is a safe sandbox to put your kids into so they can watch stuff that is kid friendly without them watching everything else. I have a pair of Roku 3 boxes and I've already ordered an Amazon Fire TV for this one feature. The inability to control what my kids watch on the Roku boxes means they will be replaced. This is an important feature to many parents.
Seems legit. They crammed functionality of an Ouya and a Roku in the same box, with the guts of a decent smartphone as opposed to some generic Chinese Rockchip/Allwinner mediocrity like you see on every gadget-selling site ever. And they kept the price competitive. Controller sold separately is kind of sad, but it is what it is. If Google Play is available as well this could be a big hit with the no-console crowd, being a fraction of the cost with a huge app library and just as capable for multimedia without paying for the extra gaming hardware. I rather like my gaming hardware, though.