Napster founder Sean Parker has claimed that, in terms of the revenue it will earn record companies, Spotify will overtake iTunes in under two years.

Speaking at a SXSW conference, Parker – who founded Napster, was an early investor in Facebook, and has invested a reported $15 million in Spotify – reckoned that the streaming service is capable of making record companies more revenue than Apple.

According to VH1 [via NME], Parker said that “If Spotify continues growing at its current rate in terms of subscribers and users, we will overtake iTunes in terms of the amount of revenue we contribute to the music labels in under two years”, before going on to criticize Apple’s mp3 juggernaut, stating that “The iTunes store, to this day, is so slow. I’m amazed.”

Spotify has taken quite a bit of stick of late: leading dance music distributor ST Holdings recently pulled their catalogue from the steaming service (though Parker’s view that it will continue to grow at a rapid rate is one shared by other digital distributors who continue to use the service), and high-profile musicians like the Black Keys have criticised it for the small percentage of Spotify revenue that actually goes to the label and artist.

As NME point out though, its overall influence continues to grow: earlier this week it was reported that Billboard’s Hot 100 chart will now use stats from sites including Spotify and Rhapsody to compile its chart placings, as well as download sales and radio play.