Spotify, the music streaming service that is tipped to be soon in line for an IPO, has today announced that it now has 15 million paying users, and 60 million subscribers overall. To put this into some context, two months ago, the company said it had 12.5 million paying users out of 50 million subscribers. Both numbers indicate that Spotify is not moving the needle yet on its proportion of paying users — it’s holding steady at 25%, but nor is it dropping as the service grows.