The process of creating fake grassroots campaigns. Astroturfing is often used specifically regarding review sites like Google Places, Yelp, Judy’s Book and more. These fake reviews can be positive reviews for your own company or slander against your competitors. Not a good idea, as it falls under black hat SEO which can significantly hurt your rankings. Google is generally able to discern legitimate reviews from fake ones, making this strategy far more risky than the potential reward.