Trump and Kiyosaki's co-authored "Midas Touch - Why Some Entrepreneurs Get Rich -- And Why Most Don't" is being published this week in the U.S. in e-book and traditional print formats. Sitting down Wednesday in a Trump Tower Manhattan office conference room overlooking Central Park, the two author-entrepreneurs appeared in a live chat streamed to Kiyosaki's and performed what their publicists said was the world's first "e-signing."

They used an iPad and Autodesk SketchBook Pro software to scrawl their signatures, which were then captured by the app, downloaded by Kiyosaki's Plata Publishing and inserted onto a special signature page that readers will see when they download the book onto their iPads. The special signature page will be available for only 48 hours, in an effort to pump up initial sales.

The book will also be available on other e-book formats including Amazon's Kindle and the Barnes & Noble Nook.

Though it could be considered a marketing gimmick, the e-signing points to trends in not only how books are published and marketed, but new directions that authors are taking to engage their readers. Books can be a big business and e-books are now outselling print books at Amazon and Barnes & Noble, analysts point out.

Kiyosaki himself has sold about 32 million copies of "Rich Dad Poor Dad," his personal finance book, and the last book he produced with Trump, "Why We Want You to Be Rich," sold more than 500,000 copies, according to representatives for his company.