Former President Donald Trump has already sold more than 100,000 copies of his book Our Journey Together, his publisher told Breitbart News exclusively.

“President Trump continues to break records, the books are literally flying off, and we can’t keep up with demand,” Sergio Gor, the president of Winning Team Publishing, told Breitbart News on Thursday. “Thousands are writing to us asking when we will have more books available.”

Trump’s more than 100,000 copies sold is 50 times more than the approximately 2,000 copies former New Jersey Gov. Chris Christie sold of his latest book.

Christie, who has been critical of Trump lately, has only sold just over 2,000 copies of his most recent book, something Trump and others have mocked as a sign of his lack of success. Trump’s book has only been out for two days longer—nine days total now for Trump and seven days total for Christie—so Trump has sold nearly 50 times more than Christie in almost the exact amount of time.

Trump’s book is selling at $74.99 for a hardcover copy and $229.99 for a signed copy, per his book’s website, 45books.com–while Christie’s is retailing in the mid-$20s per copy, according to Amazon–so the feat is even more impressive considering the cost differential between the two.

“We sold 2,500 in five minutes, 100,000 in just under ten days. An unparalleled success! We are already printing more; the demand is unlike anything I’ve ever seen before,” Donald Trump Jr., Trump’s eldest son, told Breitbart News.

Trump’s book is a collection of photos and captions—many of which are handwritten by Trump himself in his signature black sharpie marker—telling the story of his time in the White House. As Breitbart News reported, with one exclusive photo and caption, the book tells stories of such things as the moment when House Speaker Nancy Pelosi wagged her finger at Trump in a White House meeting—an iconic and historic Trump administration moment during which all sides saw something unique.