What happens when a book you've published receives bad reviews?It can impact sales—depending on who gives the review and how legitimate the review seems to readers.
If the review is just a slam, filled with typos, poor grammar, or personalized comments, most people ignore it—as do we. If the review is intelligent, well-written, and seemingly unbiased, it can cause us grief. Then we cry and cuss and stomp around, howl and gnash our teeth, cover ourselves with sackcloth and ashes, burn effigies of the reviewer. You know. The usual stuff people do when they're disappointed.
Depending on where the review was published and what was said, we might try to get fans of the book and/or author to publish contrasting viewpoints. For example, if it's on amazon or a blog, we might encourage the author to encourage their fans to post polite comments that disagree with the reviewer, or to post their own positive reviews online—but only if that was their honest opinion.
But most of the time, we don't really do anything about it. If the book is good, fans are already out there posting positive comments. If the bad review is deserved then we use that information to do better next time.
Only once have I ever personally contradicted an online review. The reviewer complained that the non-fiction book included every scripture and quote by a general authority on the topic. From our point of view, that was the selling point of the book. Need info on this topic? Here's all you ever wanted to know—and then some. So I politely stated that in their comment section. I also identified myself as the publisher. That particular review didn't seem to hamper sales. We did just fine.