It wasn't just mince pies and turkeys flying off the shelves at Sainsbury's over Christmas. According to the retailer, sales of bras and knickers are up 47% year-on-year, equivalent to selling one item of lingerie every three seconds. "Last year, in the depths of the recession, we noticed people prioritising spend on outerwear. But this year women want to look just as good under their clothes," said Sainsbury's clothing buying manager Beth Watson.