You're not playing the "cite a definition" game correctly. You neglected to include the reference to the presumably-a-dictionary you used. How am I supposed to go back to the same work, cite another subdefinition that has about a 50-50 chance of actually applying, and then argue that I'm correct while simultaneously invoking some half-assed "Amazon is really a newspaper, or maybe something involving cars" metaphor? The Internet has a well defined protocol for this dance!
Anyhow, trying to shut things down by definition only works in mathematics. Redefining away what Amazon as "not censorship" won't mollify anybody, as they can still choose to be legitimately annoyed at the perfectly legal and arguably perfectly ethical actions Amazon have taken. Acting legally and even ethically doesn't mean you have the right to not be criticized.
And, seeing as how if this is "not censorship" we don't actually have an English word for what it is... yeah, it's censorship. It's not government censorship, but it's censorship. It's also a sufficiently different kind of censorship that simply knee-jerk applying our attitudes towards government censorship may not be relevant, but English simply doesn't have the granularity to deal with this. That's OK. Everything works that way anyhow.
Amazon is a media outlet but they are not suppressing his speech. They are not stopping him from publishing the work or even stopping him from writing it. They are choosing not to distribute it. Thus the suppression test fails and it is not censorship.
Okay, we don't have an English word for it, we have to use two words instead: quality control. Just because someone decided to publish a book, it doesn't mean Amazon must sell it.
You can address that issue the same way author did it, by stating that Amazon sells stuff like "Hostel 2". Frankly, I haven't read the guys book and I haven't read Amazon's quality control policy (or whatever it's called) either, so I can't say whether the book fails the test. My point here is that most people commenting here can't say that either, for the same reasons. So why are some people so quick to side with the author and cry "censorship", when it might just be that his book is crap?
Anyhow, trying to shut things down by definition only works in mathematics. Redefining away what Amazon as "not censorship" won't mollify anybody, as they can still choose to be legitimately annoyed at the perfectly legal and arguably perfectly ethical actions Amazon have taken. Acting legally and even ethically doesn't mean you have the right to not be criticized.
And, seeing as how if this is "not censorship" we don't actually have an English word for what it is... yeah, it's censorship. It's not government censorship, but it's censorship. It's also a sufficiently different kind of censorship that simply knee-jerk applying our attitudes towards government censorship may not be relevant, but English simply doesn't have the granularity to deal with this. That's OK. Everything works that way anyhow.