Amazon's Prime Day 2025 is off to a rocky start, at least by one account. Momentum Commerce, which manages online sales for 50 brands in a variety of product categories and price points, said its Amazon (AMZN) sales plunged 41% on the opening day,

Some major retailers raise the online prices of certain goods days or weeks before marking them down in seasonal sales events, the NBC News Price Tracker shows.

The summer sales calendar now revolves around Amazon's anchor, with most major U.S. retailers scheduling competing events within days of Prime Day's expanded four-day window.

Warehouse workers and union representatives said Prime Day meant extra hours in sometimes sweltering temperatures and a heightened risk of injuries.

SuperStore electronics general manager Todd MacDuff said they saw an increase in customers this past weekend, and credits that rise in sales to the promotion they put out before Amazon’s Prime Day deals.