I recently purchased a used copy of the art historian Ursula Meyer’s Conceptual Art (1972) on Amazon for £1.76, plus international shipping and postage. It arrived in the post a week or so later after being dispatched from New York to my home in London. When I opened it, I noticed that the inside cover was stamped with the name and mailing address of the previous owner: Dan Graham. The artist was using a P.O. Box at Knickerbocker Station on East Broadway in Manhattan when he owned the book.  . . . Read more.