The audience for a book review is an essential consideration when writing a review. Take, for example, this review of In The Plex, another book about Google, from the business magazine BusinessWeek.
Because it is a magazine for business people, BusinessWeek offers a snapshot of the review, including a starred rating, almost like the "Executive Summary" of a report:
PLEASE NOTE: I do not want starred reviews or synopsis of this kind from you.
The reviewer focuses on a particular theme, one that presumably the audience of BusinessWeek will care about: "While In the Plex offers a diligently reported look at a company with $169 billion in market capitalization, it inadvertently tells the story of how an audacious business became a corporate behemoth." In other words, the thesis of this review is that In The Plex describes the fall of Google from a once-audacious company to a "corporate behemoth."
For an academic review, such as the one I have asked you to write, you may conceptualize the audience in much broader terms. You do not have to assume your audience is at all interested in business: Perhaps your audience wants to know about how the book treats Google and privacy concerns, for example. Never assume that a book has only one thematic thread, or only one interpretation.
I will add more advice on the book review in subsequent posts.