Sex Shooter is a two-disc, 270-minute interactive DVD with Hartley containing one scene with another woman and one scene with a guy. The other four hours contain interviews, behind-the-scenes footage, and God knows what else.
Some fans are hardcore. I was visiting a pornstar friend the other day who casually relayed that one of her fans had written a Star Trek spec episode for her in which she becomes Kirk's wife and takes over the Enterprise.
Nina Hartley has fans like that, so I assume that if the other four hours of Sex Shooter only show Nina Hartley asleep in the laundromat, someone would buy it.