As you may recall, streaming music service Spotify leaped across the pond to American users last month with the blessing of the major music labels. For those of you who don't recall, Spotify is trying to do for music what Netflix Instant did for streaming video: instead of a Pandora-style system that lets you listen to music that an algorithm chooses, Spotify gives you access to all the songs in its cloud to organize into playlists and listen to as you please. Well, the numbers are starting to come in, and so far things look promising: the US version of Spotify has racked up 1.4 million registered users in spite of the free tier's invite-only status. Of those users, roughly 175,000 are paying users, a...