With the final signature photographed above, novelist John Green ended his quixotic quest to sign 150,000 copies of his upcoming book, The Fault in Our Stars.

He left a short message on his blog: “I want to thank nerdfighteria for being so supportive, Stan Muller for doing everything other than signing, my brother for hanklerfishing, and everyone at Penguin for indulging my strange dream … if you want one of these signatures, I’d encourage you to preorder today from your local independent bookstore.”

Green will be the keynote speaker at Mediabistro’s Publishing App Expo, a conference on December 7-8 showing writers and publishers how to share their stories on tablets and other mobile devices.