Flickr / Derek Clark With rumors of a huge $500 million round of funding on the horizon, Uber is set to become the most valuable startup in the world.

For users, the appeal of Uber is obvious. You can get a car on demand without the hassle of looking up and calling a cab company. But it turns out it's extremely lucrative for drivers as well.

According to Uber, the median wage for an UberX driver working at least 40 hours a week in New York City is $90,766 a year and $74,191 a year in San Francisco, The Washington Post reports. UberX is its lower-cost service, where drivers use their own vehicles, similar to Lyft’s service.

For contrast, estimates place the average cab driver's salary at around $30,000 a year. That's nearly triple the income. New York City Uber drivers even make more than the average tech worker across the U.S., who pull in $87,811 a year.

Although Uber takes a 20% cut of drivers' fares, they are more efficient with less downtime because they don't have to cruise around looking for riders, they save money by not having to apply for expensive taxi permits, and can set their own hours.

Granted, Uber hasn't revealed the median income for drivers across all of the 60 U.S. cities that it operates in, but the promise of a more efficient system has lured 20,000 new drivers to join Uber's platform every month since January.