NEW YORK — The publisher of Sen. Joe Biden's memoir, an instant best-seller for the vice presidential nominee, is being reissued in paperback with a first printing of 100,000.

The Random House Publishing Group released "Promises to Keep" in hardcover a year ago. After a brief appearance on The New York Times' hardcover best-seller list, the book quickly faded, as did Biden's presidential candidacy, which ended in early January.

According to Nielsen BookScan, which tracks about 70 percent of sales, the memoir had only sold 15,000 copies before the announcement that Sen. Barack Obama had chosen Biden as his running mate. "Promises to Keep" quickly reached the top 25 on Amazon.com and was out of stock as of Monday afternoon.