It isn't just fake reviews, it's also fake accounts on web services, etc. It's an arms race where business are constantly trying to one-up their competitors and everyone has accepted that fake reviews and inflating their user numbers is, at the very least, a necessary first step to jump-starting their product.
from https://boingboing.net/2018/05/31/fake-reviews-now-generally-nec.html
Quote
Outside the publishing industry, the practice known as “review brushing” exists on a vast, industrial scale. In 2014, Haitao Xu, a thirty-year-old researcher now at Northwestern University, monitored five black-market Internet boards where companies and individuals advertise jobs posting positive reviews of their products and services, along with negative ones on those of their rivals. In just two months, Xu saw more than eleven thousand unique sellers post close to a quarter of a million jobs, paid at anywhere between “tens of cents, up to five dollars,” he told me. Since consumers typically see positive customer reviews as a more reliable indicator of quality than advertising, the effects can be major. “Stores using brushing services can increase their reputation ten times faster than normal seller stores,” Xu, who, in 2016, spent six months working in Alibaba’s fraud-detection team, told me. “A store with a high reputation is displayed higher up a Web page, attracting more customers and increasing sales.” Online sellers who do not employ brushing services, meanwhile, often find their products overlooked.
from https://boingboing.net/2018/05/31/fake-reviews-now-generally-nec.html
