And if I told that for 2 dollars a fake positive review can be done for your product and placed in Amazon, TripAdviser, Yelp... ( http://www.nytimes.com/2012/01/27/technology/for-2-a-star-a-retailer-gets-5-star-reviews.html?_r=2&hp ). This article was from 2012, but this is still a major battle area for online retailers, given the importance of reviews on onsite search and consumer preference for a new buy. Online retailers and review-based-sites have the huge task and responsibility of keeping fake reviews and bay, if they want their business model to keep on thriving - as it is.
