This is due to the fact that a lot of people have signed up for Netflix. Even if they only choose the package with the lowest price, it is still enough to bring them some revenue. They earn millions of dollars every month because of the number of subscribers.
They have original shows too that are also being watched by millions of people from all over the world. Take note that while Netflix was very profitable in the beginning, they started showing some signs of losses around mid-2017 because of the demand for new shows. The more shows that they produce, the more people that they have to hire and pay for. This makes them lose more money rather than earn them.
