A BLOOD DRIVE is under way in 10 states (439 pints collected thus far); a new collection of blood-spattered props is up for auction on eBay; fans are gathering at an under-the-radar Web site called Howfuckedup.net; and the MPAA is in a lather over a one-sheet that gives new meaning to the phrase “hack job.”These are not the trappings of your typical studio marketing campaign. They’re part of the grass-roots promotional push for “Saw II,” the sequel to what is surely the most profitable no-budget horror release since “The Blair Witch Project.” Lions Gate’s Grand Guignol blockbuster about a psycho with baroque plans to punish people who take their lives for granted was made for about $1.1 million. It grossed $100 million worldwide and became America’s No. 1 DVD in its first week on sale, a feat that makes one pause and wonder about the mental health of America’s movie fans. “It’s not studio slick and sanitized,” Lions Gate acquisitions prexy Peter Block says of “Saw II.” “We wanted to make it a hard ‘R’ and dare people not to come.” That sets it apart from the PG-13 horror titles like “The Ring 2″ and “The Fog” that have become studio staples, creating a glut in the horror market the likes of which hasn’t been seen since the heyday of Michael Myers and Freddy Krueger. By the end of this month, there will have been 17 horror releases in 2005, compared with nine in the same period last year. Halloween is now an event weekend: “Saw II” will compete with four wide releases Oct. 28. FEAR IS ONE of the most potent weapons in marketing. But it’s hard to scare people whose fears are magnified by real events. And it’s harder still to capture the attention of an audience that’s grown more adept at inoculating itself from advertising and whose sensitivity to shock tactics have been dulled by everything from videogames to Internet porn. Given these hurdles, the grisly quality of the “Saw” franchise is a blessing. At least that’s how Lions Gate exec VP of theatrical marketing Tim Palen sees it. Palen, a fine-art photographer who earlier this year came up with the one-sheet for “Lord of War” in which Nicolas Cage’s face was configured from bullets, has a flair for unorthodox ads that push the boundaries of sex, gore, fashion and camp. Studios, Palen told me, “can pound the message home, ‘Go see this movie, go see this movie.’ We have to scream louder and we have to be shriller and sharper in everything we do because we don’t have the ad spend that they do.” Hence the Web site Howfuckedup.net (which seems to have escaped the attention of the MPAA, which rules out all marketing materials that aren’t approved for general audiences). And the brash, high-concept ads like the original one-sheet for “Saw 2,” ultimately nixed by the MPAA, whose title treatment was structured around what appeared to be two severed fingers. THE “SAW II” materials are just as creepy as those for the first installment. But “Saw II” has its own hurdles. The first “Saw” was a triumph of viral marketing. Instead of building mass buzz from the top down, the idea was to let awareness bubble up from the underground. “At the end of the day, it became a bigger event than if we tried from day one to sell it to everybody,” Lions Gate marketing chief John Hegeman told me. But “Saw II” isn’t an underground event. It can’t fly under the radar. Expectations are sky high, just as they were for “Blair Witch 2.” Palen appears unfazed by the challenge. “We’ve modeled our entire campaign on what we did last year,” he says. That means more guerilla marketing. And more out-there ads cooked up and executed inhouse. Palen shot the blood drive ads himself, as he did for the last “Saw” blood drive. Those ads featured Lions Gate marketing VP Erika Schimik in a nurse’s uniform, blood smeared across her face, hands and cleavage. With a plug like that, the pints of blood — and box office dollars — should come pouring in.