Rdio just put a lot more free music in your life.

The online streaming service, formerly $4.99 per month in its cheapest form, has officially rolled out a free option that will let you listen to any of the albums or songs in its 12-million-song catalog at no cost and with no credit card information. The best part? Unlike Spotify, there are no ads. Of any kind. Ever.

On the downside, however, listening is not unlimited. (Spotify, on the other hand, is unlimited for at least six months). Rdio will give each user a customized meter that guages how much free listening they have left for the month. Once that's up, you'll have to pay up or wait til the next month.

And Rdio is a flash-based web application, so you'll have to give it a tab in your Web browser whenever you use it. Spotify, of course, is a desktop app like iTunes.

Decisions, decisions!

But hey, at least your wallet is safe.

[CNET]