Last year was a big year for Amazon Prime in India. Membership doubled from January to June, and then doubled again from June to October. Driving the fast growth, said Akshay Sahi, Amazon’s head of Prime in India, are exclusive deals, a strategy the company might deploy elsewhere.

The expansion in India has been costly, and the company is facing fierce competition from its homegrown rival Flipkart, which is fresh off a $2.5 billion infusion of cash from SoftBank. Amazon’s international losses in recent quarters have been attributed to its heavy spending to build its e-commerce business in India, where CEO Jeff Bezos has pledged to invest $5 billion. The company launched in India in 2013 and began its Prime membership program in July 2016.