Okay, I may have exaggerated a little, but you have to admit that it's difficult to evaluate a book when it's wrapped in protective plastic. The online equivalent of that barrier are reviews that don't show pictures of a book's contents, and all too many web sites do just that.
That's why I'm begging anyone who will listen, if you review a book, please show us a few sample pages so we can get a feel for its contents and quality! Telling me that a book has 128 pages and 200 photographs doesn't tell me much. Showing me that each full color photo consumes half a page sets a much clearer expectation of what I'm likely to buy. Oh, and showing me the title page publisher's contact information, credits, and index pages don't count. Amazon, are you paying attention?
Who's doing book reviews right? Hyperscale, of course. Take a look a this review for the new 4+ Publication book on the Ilyushin Il-2 Shturmovik. This is the kind of review that sets the standard all others should follow.