Amanda Knox: Diane Sawyer Special Boosts Book Sales

"Waiting to Be Heard" shot up Amazon's sales rankings after the Tuesday-night broadcast as the ABC newswoman books her next big author interview with the Pakistani schoolgirl shot by the Taliban.

Diane Sawyer delivers.

Sawyer's primetime ABC  interview with Amanda Knox has given Knox's memoir, Waiting to Be Heard, a big sales boost.

The book has moved into Amazon's top five sellers. At the end of last week, the book had not managed to crack the e-retailer's top 100 for books.

First-week sales details from Bookscan won't be available until May 8, but Amazon numbers provide a good leading indicator of sales.

Overnight ratings for the special were also strong. ABC hit a 12-week high in the 10 p.m. Tuesday slot with a 1.7 rating among adults 18 to 49 and 8.5 million viewers.

The strong bump is a good sign for publisher HarperCollins, which paid a reported $4 million for the story of the Seattle college student ensnared in the murder of her British roommate.

The news also confirms a Sawyer interview as one of the most reliable promotional vehicles for a book.

In just the last two years, specials hosted by Sawyer have given boosts to books by Jaycee Dugard, Bob Woodward, Congresswoman Gabby Giffords and a newly-released collection of Jackie Kennedy recordings.

ABC also announced Wednesday that Sawyer has nabbed an exclusive book-related interview with Malala Yousafzai, the 15-year-old Pakistani student shot by Taliban militants for advocating schooling for girls.

The interview will air in October in conjunction with the release of her memoir, I Am Malala, which is slated for publication around the one-year anniversary of her shooting Oct. 9.