This influential book was written by by Frank Bettger in the 1950s.

The Greatest Secret in Selling
Show people what they want most, and they will move heaven and earth to get it!

Ben Franklin's System
Ben Franklin had a system where he chose thirteen subjects and focused on improving on each one for a week at a time. At the end of thirteen weeks, he would repeat the procedure, completing four "sets" in a year. Frank Bettger found in Franklin's system a method of self-discipline and developed himself to be one of the greatest salespersons of his time.

[From the Great Books Series.  Also Read The Success Manual - Encyclopedia of Advice - Contains Summaries of 100+ Greatest Books & More...  ]