Collective intelligence - or crowdsourcing - refers to harnessing the power of a large number of people to solve a difficult problem as a group. The idea is that a group of people can solve problems efficiently and offer greater insight and a better answer than any one individual could provide. Collective intelligence can also be a valuable marketing tool.
David’s Bridal, the US bridal chain, employed collective intelligence by inviting brides-to-be to play online games that use photos of new dress styles to test their opinions in order to give an idea of what type of dresses will sell. 
The games-based predictive system is run by First Insight, a Pittsburgh-based start-up that is part of a broader push in the retail industry to harness the power of collective intelligence.
First Insight is similarly trying to bring collective intelligence to bear on the most unpredictable areas of fashion demand forecasting, but on a much larger scale – entering what has traditionally been the domain of the skilled buyers who use a mix of instinct and experience to make their bets.