Until seven or eight years ago Black Friday was a sales day in America, that few of us outside of the country had heard of. Since then it's grown into a global shopping phenomenon. A report released today by the website PriceSpy predicts that 1 in 3 of us plan to spend over $500 in the sale. Despite officially being this Friday, Instagram, Facebook and all the other platforms have been overrun with Black Friday ads for weeks. So what is it? Were did it come from? And are there good deals to be had or is it just manipulative marketing? To unpick all that Mark's joined by Bodo Lang - Professor of Marketing Analytics at Massey Business School.