Spotify has announced it is cutting back on its free music streaming service in its latest attempt to lure consumers to upgrade to one of the paid options. Starting on May 1, anyone who signed up before November 1, 2010 will be restricted to 10 hours of listening time per month, half of what's currently offered, and will only be able to play each track five times. Those who signed up after November 1 will see these limits go into place six months after their sign up date.

The company announced the move in a blog post today while touting the service's popularity in Europe: "People are listening to more music and from a wider range of artists than ever before, and are giving up on piracy, which is exactly what we hoped would happen. So it's vital that we continue offering an on-demand free service to you and millions more like you, but to make that possible we have to put some limits in place going forward."

The company's ad-free Unlimited and Premium services will remain unaffected and throughout May the Spotify Premium free trial will be extended from seven days to 30. Unsurprisingly, some users were taken aback by the news and have threatened to switch to competing services like Grooveshark or simply go back to piracy. A lot of them are also supportive of the move, though, claiming Spotify is well worth the $5 or $10 monthly fee.

Spotify is working hard to make its way to the U.S. and has reportedly already signed deals with EMI Music and Sony Music Entertainment already. Some speculate that the decision might have come as a condition from U.S. music labels to launch in that territory, but of course the company is not commenting on such claims.