The figures apply across all online retailers for Amazon Prime Days. Tariffs and economic uncertainty are on the minds of shoppers as they prepare for Amazon's summer Prime Day sales. But at least one company is forecasting that sales for the online sales event will break records as budget-conscious shoppers look for deals.

Ten years after Amazon launched Prime Day in 2015, this year's version of the online shopping and discount extravaganza is unlike any other in the company's history.

Amazon.com Inc.’s Prime Day sale helped boost online spending across all retailers in the US by 30.3% to $24.1 billion, according to Adobe Inc., topping its estimate for 28.4% growth for the period ending July 11.