Why all the books on Sarah Palin?

I’m sitting here scratching my head over the morning news at all the people putting out books about the Palins.  Why them?  I don’t see books coming out about the other potential candidates.  What makes the Palins so special that people keep wanting to write books about them?  or is the real question - Why is Sarah Palin such a threat that people feel the need to write stuff, as in “making stuff up” like Levi Johnston did, to discredit her?  

Maybe we should also ask - is someone paying these guys to do it?