Sony Network Entertainment had promised to launch its Qriocity Music Unlimited subscription service in the U.S. before the end of the first quarter, and today that promise was met.

The U.S., in addition to New Zealand and Australia, now have access to the service that aims to compete with iTunes, Rhapsody Zune and others.

Other than the area of availability, there's really nothing new about the U.S. launch. The full name is still "Music Unlimited, powered by Qriocity. It costs $3.99 for a customizable Internet Radio experience, as well as a "scan and match" feature that reads all the music stored in users' digital library and then allows users to stream only those songs from any Music Unlimited deviceā€¦ like a music locker.

For $10 a month, Sony's new streaming offering will function much like a typical music subscription service, with music on-demand from a catalog of 6 million titles and the ability to create playlists.

For a first-person perspective of the service, read Billboards' Midem review.

To call Sony's rollout strategy "deliberate" would be an understatement. It first launched in the UK and Ireland in December in what the company called a "road test," then added a handful of countries in Europe this January.

In addition to the limited market, the service is also limited on devices. For now at least, only Sony-made Internet-connected hardware have access to the service, such as the PlayStation3, Bravia TV sets, Blu-Ray players and so on. There is no mobile app yet for any of today's smartphones or any access by Sony's own portable devices such as the PSP.

Publicly, Sony says it wants to first focus on bringing the streaming music experience into the home via the home entertainment systems where it has a strong footprint. Sony Network Entertainment executive VP and COO Shawn Layden say the vast majority of Music Unlimited customers so far have come via the PS3.

"That's where the early adopter lives," he says.

To get the service, the PS3 must be connected to the Internet (not all are) and be signed up to either the free or premium PlayStation Plus account. Layden says there are more than 60 million of just such accounts worldwide, only a fraction of which are PSP users.

PlayStation Plus subscribers will have the service pushed to them. Others will have to manually download it.

However Sony is still not ready to go big with the "hundreds of millions" of marketing dollars that Sony Network Entertainment president Tim Schaaf at Midem promised would support the launch. Layden explains that Sony wants to take some time to identify any technical problems, add new tracks to the catalog, and so on before making much noise.

"With a product launch, you spend your mountain of money in the first three weeks it hits the shelf to get momentum," says Layden. "With something like Music Unlimited, which is a service, you first begin the service, and then roll out your plans for marketing. We'll be spending more money marketing MU six months from launch than the first day of launch."

One thing that's likely also going to wait on is the mobile expression of the service. Layden says it could come to the PSP by this spring, but it will also need to be available as a mobile app on today's smartphones, as well as other in-home devices not made by Sony.