The agreement struck between Netflix and Warner Bros. to postpone the availability of new releases on Netflix DVD-by-mail service for 28 days following their release on DVD/Blu-ray (you can read an interesting analysis of it here), means that when a new movie, say Inception, hits the shelves in DVD and Blu-ray, Netflix customers won’t be able to get it until at least 28 days later.  This agreement has served as a template for Netflix’s relationships with many other major studios meaning that many new releases aren’t available for physical rental on Netflix 28 days after release (and they typically don’t show up on streaming for at least another year).

Some studios also have something called an "output deal" with broadcasters like HBO, which means that the broadcaster gets movies that the studio releases first and limits how those movies can be sold before and after they get them. It is this deal that limits studios' ability to offer Netflix titles for streaming for 7+ YEARS.

At VUDU, things work differently.  Almost all of our movies are available the same day they come out on DVD and Blu-ray.  And because we’re all digital, our customers don’t have to suffer through the rationing of physical inventory or the headaches of getting scratched discs that are unwatchable.  All new releases are available to everyone with the best viewing experience possible, in 1080p HD quality and Dolby Digital Plus surround sound.  Our customers have told us they love the value we deliver to them.  And as it turns out, our commitment to delivering you the earliest, best movie experience possible is something that Hollywood loves as well. So rather than seeing us curtailing what we offer our customers, you’ll see us moving in the opposite direction – more movies earlier!

For an interesting read on title availability over time, check out the following article.