Yes, authors are dependent upon book reviews for sales.
But we also depend on them for warm fuzzies. Really, nothing gives us warm fuzzies like a review from a reader who love the book.
Like this one, for #terrapinSkyTango
"With a (literal) break-neck plot, filled with explosive set pieces and hard-driving characters, author Michael Warren Lucas returns to the thriller genre as if he had something to prove. He really doesn’t."