Answer:

Several years ago Mr. Card made the decision to stop accepting books to be signed through the mail. The time, expense, and risk of loss became too much. Instead, he had bookplates designed in two styles – one depicting the Dragon Army logo and the other Hatrack River – for sale exclusively at the Hatrack Store. They are all signed by Mr. Card and are sold at cost for just $1 (OSC never makes money off his signature).

He still makes himself available to sign books at public appearances which will be posted on the calendar area of the website.