How can I motivate a group of complete strangers into believing that my presentation will be beneficial to them?

In order to hold an interest in the speaker the audience must be motivated by the belief that the information presented will be highly beneficial to them.

For example, a hardware salesperson might motivate this audience by saying  “The system I am describing will save you $100,000 over the next three years.”  Who in the hardware business wouldn’t be interested in saving $100,000 a year!   The motivation statement you make must illustrate the benefits, establish rapport, and reflect the desired results from the objective statement. Have a “you” statement to keep focused on the audience. Decide on the main points you will cover and tell audience what they are using a visual aid. Be brief. Use transition statements to introduce the main points.  Recap your points before closing and tie your closing into your intro attention grabber to frame your show.