David Beckham signs for young fans during his visit Hangzhou Huanglong Stadium on June 22, 2013 in Hangzhou, China. Now you can get Beckham's signature on Facebook. - 

Retired soccer star David Beckham is releasing a self-titled book, of photographs taken of the athlete throughout his career. Beckham is pairing with Facebook for what they're calling a "global book signing," in which Facebook users can register to view the author's book release online and then receive a copy of Beckham's digital signiture on a Facebook wall. 

As the popularity of e-books has grown, so has the emergence of e-signatures. Evan Jacobs, founder and CEO of Authorgraph, a service that lets authors sign e-books for readers, has signed up nearly 8,000 authors to his service including E.L. James of the blockbuster "Fifty Shades " trilogy. Jacobs, a software engineer, came up with the idea for Authorgraph during a book signing in Seattle two years ago.

"The author was reading from his book and he said, 'ok, everyone come up and get your book signed,'" said Jacobs. "And I was like, what do I do? I have the book on my Kindle. I don't have anything for you to sign." 

Still, an athlete's digital signature doesn't have quite the same cachet as a hand-signed ball or jersey, says Matt Federgreen, owner of the Beverly Hills Baseball Card Shop, who just last year sold several soccer balls bearing Becks' signature for around $200. Federgreen says an e-signature isn't worth anything. And, he says, for many people, meeting the athlete in person is what really counts. 

"You don't have a [memory] of meeting the athlete," Federgreen said. "I remember when Muhammad Ali was signing, people waited hours for their five or ten seconds in front of Muhammad."

Follow Noel King at @noeleking