Here are some shopping-influence statistics that should get you thinking about SEO – Search Engine Optimization, Social Media Marketing and/or Online Reputation Management:

• 83% of consumers say online customer reviews influence their purchase decisions. (Source: Opinion Research Corp., June 2008)
• A word-of-mouth recommendation is the primary factor behind 20% to 50% of all purchasing decisions. (Source: McKinsey Quarterly, April 2010)
• Harvard University research on Yelp shows that a 1-star difference in reviews on Yelp may result in 5% to 9% in business gained or lost. (Source: Harvard University, September 2011)

Source: http://www.forbes.com/sites/cherylsnappconner/2013/07/07/how-reputation-management-drives-small-business/