Build suspense. Early in the speech, pose a mystery that you promise to solve. Example: Point out how certain customers’ behavior doesn’t make sense, but hint you’ve found the explanation.
Mention listeners by name. Pepper your presentation with praise for individuals in the audience. This keeps everyone listening to hear whom you’ll recognize next.
Reinforce key points with visuals. Every two or three minutes, show a slide with a one-sentence summary of the point you just made. This way, even if someone daydreams for a moment, he can catch up.