From Judith Regan's November 17th cri de coeur:

I don't know why he did it - why he did the book, and sat for the interview. Was it his own disturbed need for attention? Did he have remorse? Was he ready to come clean and make amends and do his penance? I wouldn't know until I sat down in a chair across from him.
What I do know is I didn't pay him. I contracted through a third party who owns the rights, and I was told the money would go to his children. That much I could live with.
What I wanted was closure, not money.

Yeah, or whatever.

Contract Details Specifics of Payments Between OJ and HarperCollins [Hollywood Heat]
Why I Did It [NYPost]