Sarah Palin's magic touch might be fading a bit. Although several of her recent projects have been successful, Palin's latest book isn't one of them.

"America by Heart," Palin's new memoir, has logged disappointing receipts since it officially went on sale late last month, publishing sources say. Although the book is second on the New York Times bestseller list this week (behind former president George W. Bush's memoir, "Decision Points"), its publisher, HarperCollins, hasn't ordered a second printing - a sign that sales haven't been overly brisk.

By contrast, Palin's first book, "Going Rogue," became thesecond-fastest-selling political book in history upon its release last year, according to Nielsen BookScan, which tracks industry sales. It went into a second printing three days after its release and went on to sell 2.2 million copies in hardcover, according to the publisher.

"America by Heart" (subtitle: "Reflections on Family, Faith and Flag") got a more modest launch. HarperCollins's initial press run was 1 million copies, suggesting that the publisher recognized that "Heart" was not likely to repeat the success of "Rogue."

Officially, at least, HarperCollins says it is pleased with the sales of the second book. "We're happy with how it's selling and expect to see it do well in the holiday season," said Tina Andreadis, a spokeswoman for the imprint, which is owned by Rupert Murdoch's News Corp.

In 2009, Palin spent six weeks on the road promoting "Going Rogue," hitting 33 states. In recent weeks, her "America by Heart" tour was more modest - 16 states in 10 days.

One theory within the publishing industry is that Palin is overexposed, at least in terms of drawing readers.

Palin's first book, published only a year ago, sold well enough to sate Palin's supporters, her enemies and the merely curious. It was such a strong seller in hardcover that it crowded out demand for the book in paperback and for the sequel of sorts, some in the industry say. The paperback version of "Going Rogue" has not made the bestseller lists or gone into reprint since it was issued with a new afterword by Palin in August.

The former Alaska governor and her family have been the stars of an eight-part reality series/travelogue, "Sarah Palin's Alaska," which scored record ratings for a new program on Silver Spring's TLC network in its debut Nov. 14. The program's ratings subsequently dipped.

Meanwhile, Palin's daughter Bristol was a recent finalist on the ABC show "Dancing With the Stars," turning the dance competition into a kind of proxy political event. Despite tepid reviews from the show's judges, Palin stayed alive on the program, buoyed by a wave of support from audience votes.

Sarah Palin has also stayed in the news with her frequent and combative postings on Facebook and on Twitter, where she has more than 325,000 followers.

According to her publisher, the crowds greeting Palin on her most recent book tour were similar in size to those that turned out for her first tour. The most recent promotional tour included a stop in Des Moines, which of course is the capital of the state - Iowa - that will hold the first presidential caucus in 2012.

"America by Heart" got a little pre-publication publicity when Gawker Media, the Web site operator, published leaked pages of it. HarperCollins sued, claiming copyright infringement. After a federal judge ordered the extensive excerpts removed pending a hearing, Gawker agreed to keep the material off its site - but not before both parties in the dispute drew attention to the book and to Gawker.

Washington lawyer Bob Barnett, who has handled such clients as former president Bill Clinton and former British leader Tony Blair in book negotiations, was Palin's agent on both of her books.