UltraViolet has added another string to its bow with the announcement that Amazon has agreed to use the system for online storing and streaming movies.

As the largest online retailer this is quite an addition to the UltraViolet system and may help attract more partners to push UV as the one-stop shop for cloud-based digital libraries of movies and TV shows.

"We’re very excited about the additional possibilities from a customer’s point of view that UV enables," said Bill Carr, EVP of digital at Amazon, during a panel discussion at CES 2012 in Las Vegas. 

UltraViolet has also announced that it has registered 750,000 users in the first 3 months of operations, but given the potential scale of the operation, some might say that this number isn't incredibly high. The system went live in the UK on 26 December with Final Destination 5, but has been running in the US for longer.

The aim of UltraViolet is to offer customers enduring digital rights to movies they buy. Rather than being locked into a particular device or system, you'll be able to access that title - via an UltraViolet partner - across devices on many platforms.

DECE (Digital Entertainment Content Ecosystem), the consortium behind UltraViolet is looking to announce the common file format for downloads in the next 6 months, to ensure a consistent experience across UltraViolet retailers.

So far, Flixter, Sony Pictures and Universal have all offered access to UltraViolet. Samsung has announced that its Smart Blu-ray players will stream content through Flixter this year, an important step to creating a simple path between online content and on-screen movies; Panasonic, Sony and Toshiba are also members of the alliance.

To date Warner Bros, Universal Pictures and Sony Pictures have all released DVD and Blu-ray titles that can be accessed through UltraViolet. Paramount Pictures has confirmed that it plans to offer movies through the service, with other major studios signed up, leaving Walt Disney on the outside. 

With UltraViolet potentially gaining momentum, it may well succeed in becoming the central repository for digital movie access - whether you are buying online or accessing a digital copy you're entitled to from a physical disc purchase.