From a recent interview:
I trust you answer the e-mail of your friends at no charge.
I haven’t got to the point yet where phone calls and e-mails are billable, but I am working on it. That would be happiness defined for me. What I’m hoping is to get a 900 number, so I can tell all my friends, “Call me back on my 900 number: 1-900-HITCH22.” I can talk for a long time.
But who would want to listen?
That would be the 900-number test.
For the pointer I thank Hugo. He asks me: whose 1-900 number would you like to ring?
Addendum: Here's Felix Salmon on Hitchens.