Tristan Louis has created an insightful chart. He took the top 100 movie hits for 2011 (via gross income) and examined which are available for streaming and where. He compares Neflix, iTunes, Amazon, and Vudu (which I know very little about). The conclusions are indicative, I think, of studio strategy for their films. (There are more charts and analysis at the link.)
First, iTunes, Amazon, and Vudu are very similar. With one or two exceptions, they all have the same movies available and usually the same restrictions. Some films are available for purchase only, not online “rental”.
Second, Netflix is not a preferred outlet to see the big films. None of the top 25 are available, and only four of the top 100. (Strangely, of those four, three are not available to stream elsewhere. Exclusive deals?) The reason for this, I think, is obvious — studios want viewers to pay per movie. They don’t like the “all you can eat” viewing method, with one low monthly price, because they don’t get to exploit all the “value” from their films they can. Studios can block Netflix from streaming movies but not from them offering the discs.
Last, DVD is still the way to go. The films that aren’t there will be soon, since some of them are still playing in theaters. Whether that reflects studio preference (they want to sell product, not make movies available digitally) or customer desire (I’d rather “own” something than have to watch can-be-jittery films over an internet connection, and streaming can eat up bandwidth if your account is limited, and $3.99 to watch a film only once seems high to me when I’m providing the venue) or both, I don’t know.