Reviews are massively important for online sales. A buyer on Amazon, for instance, may not even click on a product with less than four stars, much less read the reviews to find out if they seem legitimate. The fact that the product got some negative reviews is enough to push them into looking elsewhere. Meanwhile, someone who sees a product with five stars may buy it without doing much research. They trust that the other users have already done the research and reported on using the product, so they don't have to. That's not to say that reviews and stars are the only ways to sell your products, but you can't ignore how much of a difference they make.