I still hold the only reason why Marvel picked up on Anita Blake Vampire Humper is because of this:

Dark Horse Comics will publish a new series of Buffy the Vampire Slayer comics that will pick up the story of the cult TV show and act as a de facto eighth season, Comics Continuum reported.

The new Buffy series is targeted for a March launch, and the first story arc will be a four-part series that will chronicle events after the Buffy television series' finale, which aired in 2003. Buffy creator Joss Whedon will write, with art by Georges Jeanty.

Buffy already has a following as it is. Not to mention this is going to be over the next season. Many fans were upset there wasn't going to be another season to explain what happens next. Anita will only be the ugly step-sister to Buffy.