U.S. online shoppers shelled out $7.9 billion across all retailers on the first day of Amazon's four-day Prime Day sale, up nearly 10% from last year, per Adobe data.Why it matters: Prime Day is more than just a summer shopping event — it's a pulse check on U.

The first four-day-long Prime Day sale, is expected to generate as much spending as two Black Fridays, Adobe reports today, with AI tools and influencers driving growth.

Prime Day shopping events to entice cautious consumers and play defense against stiffer competition from the likes of Walmart Inc., Target Corp. and TikTok, who have launched their own discount days in response.