HBO keeps most of its online video content under lock and key. Other than snippets (and the occasional full episode) on its YouTube channel or HBO.com, most people that want to legally watch its shows on-the-go have one real option: pay for episodes on iTunes. But HBO can lower that pay wall at will—especially when it wants to promote something new—and that’s what it’s doing for its documentary series The Alzheimer’s Project. It’s even distributing the four-part series across Facebook and MySpace, and letting people take and embed the clips on other sites.

The episodes, trailers, clips and supplemental shorts will be available for free in various capacities across the social nets, iTunes and YouTube; Multichannel News notes that each venue is getting its own exclusive premiere, and will be promoting the content accordingly. The series will even go live on HBO.com May 8, two days before its TV premiere. HBO launched a similar effort for its Addiction series in 2007, but a source said the online scope of the Alzheimer’s Project was likely “one of the biggest ever” for HBO, adding: “online viewing and social media are certainly the way of the future—but it still goes against the ‘tradition’ here.”

HBO has also been doing some other things lately to try to step back from that “traditional” view: the network has been testing its HBO on Broadband Demand streaming video service in Wisconsin for about a year now, and HBO content will likely also be included as part of parent company Time Warner’s ambitious pay-to-play TV Everywhere plan in the long run.

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