Amazon released its fourth quarter earnings for 2019 today, and the company is touting big Prime subscriber numbers as one of the main contributors to a very successful holiday season. The company says it now has over 150 million Prime subscribers, and that more people joined Prime during the fourth quarter of last year than any other quarter in the company’s history. Since its last milestone of 100 million subscribers in 2018, more than 50 million people have joined.

It’s no secret that people subscribe to Prime, at least its monthly version instead of its annual one, more during the holiday season than at other times in the year, to ensure that gifts arrive for the holidays. But Amazon also attributes its particularly big swell of new Prime subscribers to the service’s availability in Brazil as of last September. Also, the company notes that it eliminated the cost (originally $14.99 per month) of Amazon Fresh, its grocery delivery service, for Prime subscribers back in October, adding another benefit to the subscription on top of Prime Video and numerous others.

Last year, we saw Amazon push to make one-day shipping a reality in a bid to prevent you from shopping anywhere else. The initiative apparently paid off for keeping Prime subscribers and adding new ones. One-day shipping comes cheap for users, but as my colleague Nick Statt shared last year, it doesn’t come cheap for Amazon.

The company says in the last three months, it earned nearly roughly $3.3 billion profit on sales of $87.4 billion, both of which smashed Wall Street expectations. Not only was Amazon’s retail division humming along, but its Amazon Web Services cloud computing division and its fast-growing advertising division both saw massive revenue jumps. That all helped Amazon offset its growing shipping costs, which jumped to an astronomical $12.9 billion as the company continues to build out its logistics network, yet were not enough of a drag to hurt its profitability.