Offices have sent their front-liners to seminars and training on Better Public Speaking.  This is a great strategy since their front-liners are the ones who face most of the customers.  They represent the company and when you represent the company well, you make sales. People will believe what you are saying.  This is especially important in ad agencies where they make their sales whenever a company takes their ideas and makes it into a billboard or a print ad or even a commercial.  That is the time when they make a sale.  So usually the people who do this are good in public speaking and will be able to make their audience visualize what they are saying.