Amazon has announced the third incarnation of its annual “WOW, look how cheap we are” Prime Day fire sale festivities, and this year’s deals last for a full 30 hours.

Though Amazon Prime Day is officially on July 11, some deals start on July 10 at 6 p.m. (PT). But perhaps the biggest news this year is that Amazon Prime Day is also landing in China and India — two massive markets for the ecommerce giant.

Perhaps this should come as little surprise given that Amazon’s annual Prime subscription service landed in India last July, followed by China a few months later. But Amazon Prime Day has emerged as a major deal in the online retail realm since it kicked off back in 2015 — Amazon claimed back then that it would be bigger than Black Friday, and that claim possibly has some merits.

Amazon has been doubling down on its efforts to encourage shoppers to sign up to its annual Prime membership in recent years, and it now includes not only Prime video streaming and free two-day, same-day, and two-hour deliveries (on some items), but also photo storage, music streaming, Kindle book lending service, cashback on debit card purchases, and special deals around Twitch’s video game streaming service.

But the ultimate aim of Amazon Prime isn’t to garner consumers’ $100 annual fee — it’s more about locking users into its ecommerce ecosystem. If someone is paying $100 a year for a membership that gives them all kinds of exclusive perks, including free speedy deliveries on almost any item, they’re more likely to do all their shopping through that service. In some regards, Amazon has already won the online retail battle in many Western markets, but after it recently announced plans to enter the brick-and-mortar world in a big way through its $13.7 billion acquisition of grocery giant Whole Foods Market, the company is going all-in on its attempt to become king of commerce offline, too.

In other parts of the world, where Amazon’s online footprint is a little more modest, the company still sees huge potential for growth. In China, companies such as Alibaba’s Taobao and JD.com trump Amazon, while in India Amazon has historically played catch-up with local players, such as Flipkart and Snapdeal.

If Amazon can make a success of Prime Day in China and India, it could see a surge in reputation, mindshare, and long-term usage. Tying a huge Black Friday-style sale to its annual Prime subscription could be enough to lure Flipkart and Taobao stalwarts onboard — and if Amazon can do that, it stands a much greater chance of winning the longer term battle in what are undoubtedly two gargantuan markets.