June 24 : Online spending among shoppers on the first day of Amazon's Prime Day rose 5.3 per cent from a year earlier to $8.3 billion across U.S. retailers, Adobe Analytics said on Wednesday. The four-day shopping event, which started on Tuesday and is being held earlier than usual this year, will be a litmus test of U.S. shoppers' spending power as the focus shifts to essential goods. Here are some key details: • Online spending on Tuesday is tracking ahead of its projections and marks the