US eCommerce accelerated over the past year, leading to a rise in the online retail penetration rate in 2016. Online retailing continues to illustrate its resilience and strong growth year over year. The fastest online category growth will continue to come from the pet category, while consumer electronics, clothing, and housewares drive absolute online spend. This forecast details growth across 31 product categories, with historical data going back to 1998; it also calculates the share of online retail sales for each product category.