Just in case you've been head-down into your data models for too long, in the US the Friday after Thanksgiving is called Black Friday. Traditionally this is a day for massive sales and steep discounts to ensure that Americans start their holiday shopping with gusto.  Over the years, Black Friday has been creeping earlier and earlier in the week and now starts on Thursday for some of the most desperate shoppers. These originally were brick and mortar store sales, but these days Black Friday ...