(Yes, it’s an adorable kitten reading a book. All to get your attention.)
How do you market a book without reviews or testimonials? The answer is you don’t. Book reviews sell books, there’s no question about it. And for indie authors reviews are an even more important tool, because some e-book marketing sites won’t even accept an ad if the book has less than 4.0 stars out of 5 in average (I find this rule very strange), so without reviews or with a poor review average you will have little chance to get your writing out to a wider audience.