Spotify to surpass iTunes in two years?

Says Sean Parker, the co-founder of Napster and current investor at European streaming music service, Spotify. During recent SXSW festivities, the entrepreneur stated:

“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.”

At its current growth rate he does have a valid point, however it only makes sense if everything remains the same, but how often does that happen in this ever-changing world of technology. What do you guys think?

Source: Billboard