The advancing retail sales are driven by 3 engines: Rising stock markets (fueled by climbing company profits), a healing job market (partly fueled by growing exports) and a recovering home market (rising house prices and sales fueled by a stronger economy). All these trends are raising the wealth of the consumers, allowing them to improve their life standard by spending more money. Maybe some of the retailers, for instance American Apparel, also benefitted from their sexy offerings and marketing campaigns.
I reckon that this comfortable constellation will continue in the coming months. The raising retail should lift the company profits further which will translate into higher incomes and more consumer spending - a virtuous circle.