The author of over a dozen books, Robert Collier was decades ahead of his time in writing down ways for man to improve his lot in life. He wrote "Secret of the Ages" during an active and successful life developed upon basic ideas which opened up new vistas of living for countless multitudes of people. Brought up to be a priest, he worked as a mining engineer, an advertising executive and a prolific writer and publisher. The Robert Collier Letter Book earned Robert Collier the distinction of being one of the greatest marketing minds in history. Robert Collier sales letters were successful because he wrote to his readers' needs. As an expert in marketing, his sales savvy and writing expertise placed hundreds of millions of dollars in his clients' pockets.