Spotify insist they are the near-mythical iTunes killer

Spotify is going to outstrip iTunes. In a couple of years. According to Spotify:

Speaking at the annual South by Southwest (SXSW) conference in Texas, on a music discussion panel, the Spotify and Facebook investor [Sean Parker] said: “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.”

Well, yes. There is a rather large "if" there; there's also a secondary "if" that assumes that new subscribers and users will consume music at the same rate as earlier adopters. There's also a third "if", that this might rely on iTunes staying where it is.

Even so, this feels like the first time a potential iTunes killer out of the dozens that have danced in front of us over the years could actually provide a decent challenge. That has to be good news, right?