According to the Statista chart based on data from Edison’s annual radio report, Pandora has a 31 percent share of the music streaming market. This is based on active listeners (tuning in more than once a month) rather than paid listeners, which represents a far smaller group. It is difficult to directly compare Pandora to iTunes because of the different business models: iTunes Radio offers unlimited free listening on all devices, but users can avoid ads by signing up for iTunes Match. Apple has not released any recent reports on the number of active listeners since it announced it had acquired 11 million shortly after the service went live.

Pandora’s percentage would suggest that iTunes Radio and iHeart Radio (third and second place, respectively) have around 20-21 million listeners. While users can hop between services freely (and at least one report has suggested that 92 percent of iTunes Radio listeners also find time for Pandora), that figure would suggest that iTunes Radio is growing at the fastest rate of the top three services, and is likely to overtake iHeartRadio in the next quarter or two — particularly if iTunes Radio expands to more countries (it added Australia last month, and plans to add Canada, the UK and New Zealand in the foreseeable future).

This spells trouble for Spotify, which is already an international service and well-regarded for its $10 per month “millions of songs on demand” streaming option. Nevertheless, it was rated at six percent share, followed by Google Play All Access at three percent. Rhapsody, Slacker and TuneIn Radio all took only two percent share.

First things first, I find this incredibly impressive. Remember, iTunes radio just launched last September. It does have favored nation status (an automatic place in the iTunes infrastructure), but still, well earned.

I also wonder what it is that keeps Pandora so solidly locked in first place. Is it great branding/marketing? The value of being first to market? I wonder what this list will look like in another year.