Which music streaming service do YOU use most often? A recent study found that iTunes Radio, which only launched last September, is now the third-most popular choice for music listeners in the U.S. The survey found that iTunes Radio had already surpassed Spotify and finds itself on the heels of iHeartRadio. The study, which polled more than 2,000 Americans, found that Pandora is still the undisputed leader in music streaming popularity in the U.S. – nearly one in three of those polled used Pandora in the last month, while no other service managed to crack 10 percent. Even though it still trails iHeartRadio, the survey is a big win for iTunes Radio, which had more than 20 million users only a month after it launched. Reports suggest iTunes Radio will surpass iHeartRadio by the end of the year, and it’s not hard to believe – Apple’s streaming service is integrated into every version of iTunes – which has a user base more than 600 million strong – meaning there’s plenty of room for it to grow.