I recently had one of the toughest public speaking engagements of my career. It was a three hour afternoon session on Martin Luther King day in Baltimore, Maryland. It was difficult for many reasons, but one of the most trying was that the audience consisted of all the employees of one company. They ranged from the lowest level to the highest level in the company.When you have all managers or all executives, it is relatively easy to hone in on their interests and concerns.
When you have such a varied group you have to 'bounce around' and not spend too much time on the interests and concerns of any one type of audience member. If you do, you will lose the interest of all the other groups.