We're spending £740 million a year on downloads for our mobile phones, according to a new report.
That huge rise, 18 times more than we spent three years ago, has happened as mobile technology gets better.
One in three of all downloads is a ringtone, making them our favourite mobile purchase, followed by games, which make up a quarter of downloads.
But as mobiles get more sophisticated, it's thought we'll be buying more real music to listen to on them.
Lots of mobile companies are trying to set up deals that will let them use on-line music shops, like Apple's iTunes.
But it's not all been good news for download companies, as some of them have been accused of tricking kids into signing up for expensive services.