Winamp won far before Spotify was even a contender. It won in another time. Spotify is winning mostly because people don't want to spend money for songs anymore and they don't give a damn if they own them. Which is not to say I don't like the practice, it doesn't matter to me.
They frequently didn't spend money for songs to start with they just stream them instead of pirate them which however much people complain about the revenue is certainly more than the zero they got from piracy.
The degree to which people didn't want to pay for music was kind of obvious when people needed mp3 players sufficient storage that filling them legally would have required as much money as a down payment on a house.
