U.S. online sales jumped 9.9% year over year to $7.9 billion on Tuesday, the kickoff of Amazon’s Prime Day megasale, according to Adobe Analytics

Online spending is expected to surge to $23.8 billion across U.S. retailers during a 96-hour Amazon Prime Day event this week, according to an Adobe Analytics forecast released on Monday, as shoppers seek strong discounts on back-to-school gear ranging from apparel to electronics.