It is mentioned in Melissa's FAQ page that even she doesn't know how many books will be in the series, only that she has a huge outline for it.
So what do you guys think? How many Blue Bloods book will be published?
I am hoping for a double digit number, like 12?
Though, I am also hoping that it wouldn't be boring and lose itself in the story knowing that for a long outline most of the times there should be fillers.
But it would be such a shame for some of the books just to be fillers. Imagine waiting for one book to be published year after year only to be disappointed that there was really nothing exciting that happens.