‘True Blood,’ From Vampire Sensation To HBO Ratings Giant

“True Blood” has been one of HBO’s biggest ratings hits. HBO In 2008 and 2009, a strange phenomenon bit American pop culture when vampires, formerly just another horror sub-genre, suddenly seemed to be everywhere. The “Twilight” film franchise is largely credited with spearheading the craze, and HBO, always eager to stay on the cutting edge, soon…