The shift to online retailing over the last five years finally caught up to and overran U.S.-wide delivery capacity during last year's holiday season. According to Forrester Research, online retail sales will grow by an additional 60 percent over the next five years. This kind of sea change has stretched the ability of physical networks to keep up and the shortage of drivers had further exacerbated this situation. Instead, technology has become more important to meeting retailers' holiday delivery challenges by helping to improve the productivity of existing resources and offer a greater array of delivery services being demanded by consumers.