Simon & Schuster’s Margaret K. McElderry Books imprint is currently running a three-week online promotion, offering a free web-only version of Cassandra Clare’s City of Bones, the first book in the author’s Mortal Instruments urban fantasy trilogy, which has more than one million copies in print.

Via a partnership with LivingSocial, which has created Facebook applications such as Visual Bookshelf and “Pick Your Five,” Simon & Schuster is making a version of the book available for reading on a LivingSocial landing page for the series through August 5.

The web version of the book will also be available through August 10 on S&S’s own Mortal Instruments promotional site, which in addition to featuring the limited-time Web version of City of Bones, also offers a book trailer, interviews, audiobook excerpts and videos.

In other Cassandra Clare news, the author will be appearing at the Bryant Park Reading Room in New York City on August 22, in an event that author Holly Black will emcee. Additional information about the event is available at the author’s Web site.