When people are looking for a restaurant to eat at, when people are looking to travel somewhere, when people are looking to buy something the first thing they do is look at reviews. People will ask their friends for recommendations. People are looking for social proof and validation. No one wants to be the guinea pig so their looking for socially proven solutions. They want to know that if other people have done it then they can do it too. Everyone is looking at each other for what is good. People are looking at you when you write a review or make a recommendation. When you get the social proof people need then you are more likely to make a sale.