Self publishers often obsess about getting their books reviewed. I've written about how book reviews matter to authors, but the real question is, do they matter to book buyers? As usual, it depends on the specific circumstances. A publishing company with sales reps who are in regular contact with bookstores may be able to convince them to stock a book they would otherwise pass on, based on a pending review in a large market media outlet. Same thing goes for scheduled author appearances on TV. But that's about selling books to bookstores, not to readers, and there's a lot more involved in getting bookstore stocking than one good blast of publicity.
Book reviews on Amazon help sell books, if they are positive, but only if the book product page is drawing visitors. Otherwise the reviews go unread. You can always spot a book for which the publisher or author has made a big pre-release push with book reviewers, because the product page on Amazon will display dozens of glowing reviews before Amazon even has the book for sale. But reviews on Amazon don't alert people to the publication of the book the way print media reviews do. I've long been convinced that the most effective book reviews in terms of increasing sales are those that serve as free advertising for the publisher to promote the fact that a well-known author has written a new book. The author's fan base probably don't read the review, they're afraid the reviewer will spoil it for them. They just make a mental note to buy the book next time they see it in a bookstore.
Authors who put a lot of effort into getting newspaper or magazine reviews for self published books that aren't stocked in bookstores are largely wasting their time. You can't expect many people who read the review to jump through hoops to order the book if it's not at the local bookstore. The exception would probably be self-help type books that offer a solution to a specific problem. I've frequently been contacted by authors trying to figure out the best way to break into some review publication or another, and I'm sure they are universally disappointed with my reaction of, "Why bother?"
When it comes to reviews online, the best book reviews for generating sales aren't written by professional book reviewers, but by people with a good reputation and a large following. When a big name blogger reviews some book that has no relation to the subject matter of the blog, some number of readers will buy it because they were already interested in a book on the subject and have faith in the blogger's judgment. It's just a new form of word-of-mouth, which remains the best way to sell anything. So don't get carried away trying to get reviews in the magazines dominated by large trade books, it's not a business model that works well for self publishers.