If they do for others, I'm not aware of it, but I know they don't for him. If anything it costs him money as what they offer is hotel and first class airfare, neither of which he takes them up on--or at least not their particular accommodations. What it can translate to are increased book sales because of the buzz it creates when he does tours. Honestly, I don't think sweetening the financial pot would mean enough to him, though, to give up his time and going through all the stress of a book tour.