[afabisch]

An Amazon review is not comparable to a review in a scientific journal. In a scientific journal a review is done by experts of the field and they invest a couple of hours / days. Scientists do this because it is part of their job. It is a contribution to the scientific community.

[gmueckl]

The academic reviews I write take me about one to three days of work. I have to work through a usually densely written paper, maybe read up on some background that I'm not entirely familiar with, develop a good understanding of the content, judge it, find places where the authors might try to hide some downsides of their work (it happens!) etc. Only then can I sit down and write an honest review.