This does not seem to be an effective way of helping others, but for those who are aware the power the spoken word has, serving others through speaking is not something that is ridiculous or impossible.
Being able to impart knowledge or teach something to another person is also a form of helping them gain a positive element in life. Speaking of things that would be beneficial and helpful to others would indirectly help to serve their needs for guidance and information. Speaking within the teaching format also is another way of imparting helpful information to others who would want to learn about what is being spoken and for those who simply just want to learn more.
Being prepared with the relevant material would create the circumstances to ensure the speaking exercise helps those around. Besides the actual act of speaking, there are many other verbal ways of communicating the substance of what is intended to be gotten across to the listening party. At speaking engagements, the individual is basically imparting knowledge for those present to be able to learn something from what is being presented. Those listening will be able to put into practice just what they heard and derive the same level of satisfaction as touted by the speaker.
The power of speech can also be used as a platform to influence others into taking on speaking engagements to encourage and build confidence. When these two elements are present it would be very unlikely for the speaking process to become a waste of time. The use of encouraging words and phrases will also help the listener to want to commit to doing better, thereby further helping to serve others and creating a more comfortable and understanding platform. Speaking engagements can also have the positive effect of a good guidance tool for the listening audience.