I finally asked and was given two answers.
The first is that it is actually harder to get into the schedule, because of the bookstores and ariports.
The second was that only Southern Authors want to to the Southern signings and then their PR reps only want major cities.
I wuld think Charleston would be seen as a major city.
Savannah, Charleston, Birmingham, Atlanta, Dalls, Houston, Baton Rouge, NO?, The Research Triangle,
Columbia, Memphis, Nashville, Richmond, New Port News, Asheville, Greensboro, And I am missing several states.
They could do an entire Southern tour!