Amazon is gearing up for its largest-ever Prime Day event, extending the popular summer sales bonanza to a full four days for the first time. Kicking off at 12:01 a.m. Pacific Time on July 8 and running through July 11, the 96-hour shopping marathon aims to attract new Prime members and give existing subscribers access to exclusive, time-sensitive bargains.

The extension marks a notable expansion from previous iterations of Prime Day, which originally launched in 2015 as a 24-hour promotion. Over the years, the event grew to 48 hours and later included a second Prime-like sale in the fall. This year’s move underscores Amazon’s aggressive push to dominate mid-year retail sales, a historically sluggish period for many retailers.

In a shift designed to boost engagement and create urgency, the company will introduce themed “deal drops” that change daily and are only available while supplies last. This strategy, which taps into consumer fear of missing out, builds on previous invite-only and limited-time offers that proved successful in driving fast purchases.

Beyond the consumer frenzy, Prime Day plays a critical strategic role in Amazon’s business model. The event serves as a catalyst for attracting new subscribers to the company’s $139-a-year Prime membership program, which provides perks like free shipping, streaming content, and early access to sales. It also boosts Amazon’s own product lines, including Echo devices, Fire tablets, and private-label brands.

The event has become a key driver of revenue not just for Amazon, but for the broader retail industry. Competitors often roll out parallel sales to capture some of the Prime Day momentum. This trend has effectively turned the event into a major retail holiday, second only to Black Friday in terms of reach and impact.