Waterstone Entertainment has optioned screen rights to Og Mandino’s bestselling self-help book The Greatest Salesman In The World into a feature film. This is a book that has sold over 25 million copies. Waterstone, which just wrapped the James Franco-Winona Ryder-starrer The Stare, is headed by producer Jeff Kalligheri and Texas real estate developer/producer Stephen Bowen. They are producing with Dave Blanchard, who’s CEO of The Og Group. Published in 1968, the book focuses on Hafid, a poor camel herder who seeks money to fund a dowry to marry the daughter of a wealthy man. This leads him to 10 scrolls that hold the secret to wealth and success. “I have been a huge Og Mandino fan since my youth,” Kalligheri said. “It is time for Og’s work to hit the big screen.” They are out to screenwriters.