Once upon a time, there were VHS videocassettes, which could hold a movie, a few trailers, and nothing else. When DVDs hit the market in 1997, they could hold not only a movie and trailers, but subtitles in multiple languages, multiple soundtracks and menus for navigation. However, DVDs were initially much more expensive than videocassettes, and their usability features weren't always enough to justify the price difference. So, home video distributors hit on a strategy of adding value with commentaries and "the making of" documentaries. Before long, they learned that they could release the same movie title two or three times, each time adding more special features. A small but determined group of fans would buy every version, just to be sure that they got all the special features.
Today, we've become accustomed to getting a commentary and some documentaries on every DVD. In fact, many people won't buy a DVD if it doesn't have a sufficient number of special features; they'll either rent it or watch it on a Pay-per-View service. I used to be one of those people, but I recently took a look at a wall full of DVDs and realized that 1) I had never watched them more than once, and 2) I rarely watched any of the documentaries or listened to the commentaries.
And so we come to Blu-Ray and digital downloads. Early Blu-Ray discs had far fewer special features than their DVD counterparts, although that gap is narrowing every day. Digital downloads generally don't have special features (except for subtitles in some cases). Is the presence or absence of special features going to drive user acceptance, as it did with DVD?
I don't think so. While Blu-Ray has been far from a big success, it's clear that consumers are buying it for image quality, not special features. Digital downloads are being rented and bought for convenience; the absence of special features is actually a benefit, because it keeps file sizes smaller and shortens download times.
The implication of all this is that commentaries and documentaries are on their way out. As a former DVD producer, I can tell you that special features cost a lot of money. As they're increasingly seen as "nice-to-haves" rather than "must-haves," producers will cut back. By and large, I don't think that viewers will miss them.