In 2012, Facebook bought Instagram for a jaw-dropping $1 billion. At the time, two-year-old Instagram had just 13 employees and 30 million users. Now, though, Facebook’s bet on Instagram has clearly paid off: Instagram has 400 million users—more than Twitter—and is bringing in money at a breakneck pace.

Aside from Facebook’s own app, Instagram is generating more revenue than any other part of the company. Credit Suisse now estimates Instagram’s revenue for the first three months of 2016 was $570 million—a tenth of Facebook’s revenue for the quarter—and analysts say it will generate $3.2 billion in revenue in 2016 overall.

Instagram started rolling out advertising on its platform three years ago. Its monetization efforts, which include premium video and dynamic product advertising, are picking up, and Credit Suisse analysts say premium video and Instagram will continue to drive ad revenue across platforms. “Our projection for consolidated ad revenue of $5.24 billion in [the first quarter] reflects our projection for $573 million and $260 million in contribution from Facebook’s Instagram and premium video ad product, respectively,” the team says. Its real strength is in mobile advertising revenue, however—Credit Suisse’s analysts say mobile ad revenue for the first quarter will grow 78 percent year-over-year, compared to 3 percent growth for desktop advertising revenue.

Much of Instagram’s recent growth has been international. More than 75 percent of its users live outside the U.S., according to an Instagram blog post from September. “Among the last 100 million to join, more than half live in Europe and Asia. The countries that added the most Instagrammers include Brazil, Japan and Indonesia,” the company said. If Instagram can continue to grow its user base, it could become Facebook’s third platform with one billion users—the others being Facebook and WhatsApp, the messaging platform Facebook purchased for $22 billion in 2014.