It’s fall, I’m feeling intellectually fit, and I’ve decided to scale (or die trying) the linguistic equivalent of Mt. Everest: Sanskrit. From here in Vermont, the closest bookshop with anything about Sanskrit would be Schoenhof’s Foreign Books in Harvard Square. If you ever go to Schoenhof’s, ask to speak to Dean. From Armenian to Zulu, Dean knows everything.
Schoenhof’s on Mt. Auburn Street in Harvard Square
As a fallback, I went to Amazon and picked out A Sanskrit Primer by Madhav Deshpande of the University of Michigan. The reviewers mostly all loved this book. Only one snag: it’s got no answer key.
Now, answer keys are a touchy subject. People learning a language at home want one for obvious reasons. A teacher using the same book in the classroom, on the other hand, doesn’t want to give the students their homework answers on a silver platter. Tuttle tries to compromise by writing in the prefaces to our language books that you can get an answer key if you write us and ask for it. Knowing that, I wrote Dr. Deshpande, and (good luck trying this with JK Rowling) he wrote back within an hour. A key exists. Problem solved.
So what’s my beef? You gotta understand how much power you have as a reader and reviewer. Even a well-intentioned pan can slaughter a good book. Amazon and BN.com do nothing to vet reviews, and publishers have little chance to correct them.
A truthful consumer review that talks about a book, warts and all, can be more persuasive than effusive praise. However, when you find a problem with a book (and you will), write the publisher! Dig a bit. We like to hear from you. If the publisher doesn’t help you out, well, then they deserve it if you go rogue on them. But if they do respond, you’ll have made a friend and may get some useful information that’ll make your review even better.
Language Omnivore 
I like how you are urging the reader/consumer to be an active and responsible participant in a book’s success/failure, rather than passively accepting (or not) what’s been handed to them. Writing the publisher is not something I would ever think of doing, and I actually AM in publishing, so thanks for the suggestion!
Thanks, Michele! Honestly, I’ve written a couple of poison-pen reviews myself, and I’d be lying if I said throwing a pie in the publisher’s face doesn’t give you a moment’s pleasure. But a better outcome is to get your problem fixed and make a friend of the marketing people, right?
Since you’re in publishing, no doubt you know that no publication, however diligently edited, is perfect. If you want to underscore a snag in your review, a gentle way to do that is with a sentence like: “Readers will note that, on page 347, the Japanese for ‘dog’ is ‘inu’ and not ‘iny’, which no doubt the editor will correct in the next edition.” That’s the constructive way to say: “Editor, please flag this for correction in the next edition.”