A 30% increase in positive tweets is 4x more more effective at driving sales for a video game than a 30% increase in ATL advertising budgets

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Source:  Report by Deloitte, reported in The Wall Blog, 19th April 2013
Methodology: "The Deloitte study, ‘Tweets for Sales: Gaming’, analysed 100 best-selling Xbox and PlayStation 3 video game titles of 2012 in the UK and looked at the impact that Tweet sentiment and reach have on sales."