U.S. retailers crossed a historic new threshold over Thanksgiving weekend as consumers set new records for e-commerce activity and embraced mobile shopping like never before. The record-breaking $5.03 billion spent online on Black Friday -- a 17 percent increase from a year ago -- was in line with expectations. Consumers spent about $43.42 billion on e-commerce holiday shopping from Nov. 1 to Nov. 26, about 18 percent above a year ago. Mobile devices were used for 54.3 percent of visits and 36.9 percent of online revenue on Black Friday.