This follow-up e-mail arrived later in the day after the earlier one. I assumed no permission was needed, but apparently others were more cautious:
The Guild's staff informs me that many of you are writing to ask whether you can forward and post my holiday message encouraging orgiastic book-buying. Yes! Forward! Yes! Post! Sound the clarion call to every corner of the Internet: Hang in there, bookstores! We're coming! And we're coming to buy! To buy what? To buy books! Gimme a B! B! Gimme an O! O! Gimme another O! Another O! Gimme a K! K! Gimme an S! F! No, not an F, an S. We're spelling BOOKS!