Holiday sales reliably spike in December for a number of retail categories, according to the census data — notably department stores and other general-merchandise stores; clothing and accessories stores; electronics and appliance stores; and e-commerce sites, catalog companies and other “non-store retailers.” While other types of retailers (such as home-improvement stores and car dealers) exhibit different seasonal sales patterns, overall U.S. retail sales are tilted toward the holiday season: November-December 2013 sales made up 18.14% of sales for all of 2013, according to the census data.