JK Rowling: writing on napkins to billionaire in less than 10 years

The headline talks about Google pair make billionaire row, referring to Larry Page and Sergey Brin, each estimated at $1 billion. I found it more interesting to see that JK Rowling, author of the Harry Potter series, has become a billionaire. That’s pretty dramatic for someone who writes books to have generated that kind of money in the 21st century.