Despite a slow start to the Prime Day summer sales event, U.S. online sales reached $24.1 billion with retailers offering deeper discounts than last year.

Online spending soared $24.1 billion across U.S. retailers during the stretch from July 8 to 11 – dubbed "Black Friday in Summer", outpacing Adobe Analytics' prior forecast, as eager shoppers rushed to snap up deep discounts on back-to-school essentials.Retailers recorded online sales growth of 30.3 per cen

Adobe Analytics reports that the start of the newly extended four-day Prime Day on Tuesday marked the single biggest e-commerce day so far this year. It has...