"The extended edition of Tune In has sold out and is now unavailable. Another print may or may not be scheduled at some future time. The e-book (issued in two halves) IS still available, but it’s UK only. My US publisher, Crown, wouldn’t issue the extended book and couldn’t agree terms for the e-book. I’m sorry about that, for me and for everyone in US who wants to buy it, but I can do nothing about it."
And if you're wondering if the book is worth reading, here's a review.
Below are links to the e-book on Amazon (UK).