While there are still a small number of questions on the site, I think it would be important to get a consensus on tag organization. It becomes trickier to enforce a policy when you already have a thousand existing questions violating the policy.
We have an ebook-readers tag - this seems largely redundant to me - that's like having a programming tag on Stack Overflow.
We have an amazon tag - this is fine if it refers to the Amazon website but redundant on this question, which has nothing to do with amazon.com and simply uses it to identify the Kindle (which is produced by Amazon).
Although not terribly important, I feel the digital-rights-management tag should probably point to drm. There are no questions with the drm tag, but I think people recognize the acronym "DRM" more readily than its expanded form.
In my opinion ebook-readers is an ambiguous tag. I think we should blacklist it and replace it by ebook-devices for the hardware devices and ebook-viewers for e.g. epub reading software on Android or PCs.
It would be nice to have a hardware tag reserved for questions that actually deal with hardware questions like "The touch screen of my reader does not respond, can I replace it." (I know that question is crappy, but there may be better ones if somebody actually has the problems).
Whether or not the amazon tag is appropriate, largely depends on what the definition is. One of the things we certainly have to do is come up with descriptions, that guide first time posters of questions, as well as guide more experienced (re-)taggers in applying the tag to the right question.
It is difficult for me to judge whether an amazon is appropriate if there is there is no tag definition for that tag.