Let's get one major exception out of the way first: There is some sense behind blockbuster productions—your Dark Nights and Harry Potters—being rolled out over time across the globe. "If you tried to release [one of these tent-pole films] on all platforms at the same time, it would drastically reduce the profitability of the film," said Keith Calder, producer of films such as the indie hit The Wackness, in an online discussion on the topic earlier this year. There are a variety of reasons behind this assertion, including how profits are shared between distributors and theaters, and because most theaters refuse to show films that are simultaneously available as VOD (video on demand). Further, the marketing for such a juggernaut, which often involves logistics like jetting the stars to the various premieres around the world and utilizing press and sales in one region to build buzz in the next, would be abominably complex for a simultaneous global theatrical release.

But the merits of simultaneous release—on multiple platforms (and, by default, in multiple territories)—begin to surface when we look at specific projects that aren't part of the blockbuster system. A number of smaller films, including 2011's Margin Call, have demonstrated success with multi-platform release. Or, skipping theatrical release altogether, let's take a look at the much-lauded release strategy of Louis CK's recent concert film. Instead of selling the rights of his standup special to HBO or another network, CK funded and released the special himself as a $5 download on his website. Just 12 days after its release it had generated $1,000,000, quadrupling his production cost. CK, who detailed, with dollar amounts, the whole endeavor on his site, took great care to make sure the download function worked flawlessly: "Development of the website, which needed to be a very robust, reliable and carefully constructed website, was around $32,000," he wrote. This cost is surmountable for all but the most shoestring production budgets. And if you do have a tiny budget, which means you likely don't have a fanbase as large as CK's, then you can probably get away with a cheaper website production because the load it has to handle smoothly will be smaller. Or you could skip building a sales module all together and partner with an existing retail site and give up a portion of the revenue. Point being, selling downloads online has a very low entry barrier. So then why wouldn't a large production company like ITV Studios, the producers of 56 Up, not immediately make the film available for download? Welcome to the rabbit hole.

"Each film is a little different in how they roll out," said Simon Kilmurry, the executive director of the POV documentary series on PBS, which has been airing documentaries for 25 years. "With international titles, there may be different obligations depending on who financed the film and what deals they made with different networks in different countries. All those deals come with certain windows where it has to show on one platform for a set amount of time before it's allowed to show elsewhere."

Eddie Schmidt, an Oscar-nominated filmmaker and former president of the IDA (a non-profit organization that promotes documentary films), added, "If you're getting money from X company they may have a foreign service deal with Y company. For example, if HBO funds your film then you are of course beholden to having it released on HBO and having it roll out on other platforms as they permit." Schmidt continued, "If you're a large multi-national, or a US company that has made foreign 'output deals' for your film or shows in foreign markets—this could be TV/broadcast, but could be theatrical too—then you can only do what they permit; there can be 'holdbacks' on digital exposure. They want exclusive hold of the product for X amount of time."