The introduction of the speech is the most important part of any presentation or talk that you give. If you nail the introduction of a speech, you have guaranteed yourself a captive audience. If you don't capture your listeners with the introduction, however, you may find yourself fighting for their ears throughout the rest of your presentation.
Introduce the Subject
Most people that walk into a lecture, presentation or pitch session know what they are getting into. However, the introduction of a speech should still give them a brief reminder of exactly what it is that they are going to hear. You want your audience to be clear about what you are there to talk to them about. By the end of the introduction, the listener should have no questions about what the topic being addressed is, even if he had a few before the speech began.
Your introduction should raise certain questions for the listener about your topic. The desire to have those questions answered causes the listener to pay attention. For example, when giving a speech on a product, you could ask questions about the lack of a product that meets certain needs of customers. The listener then pays attention to see how your product meets those needs better than existing options.
The introduction is your best chance to create a sense of excitement about the topic you are speaking on. The best public speakers in the world use a sense of drama, pacing, humor and clarity to amp up the listener's interest in the speech to come. For a great example of how this is done, watch any archived footage of Steve Jobs speaking at Apple Keynote presentations. Jobs is renowned for his speaking ability, and is one of the best in any industry at creating excitement at his events.
Present a Preview
During the introduction to a speech, let your listeners know what you're going to tell them about during the next several minutes. Akin to the introductory paragraph of an essay, the introduction to your speech should just briefly touch on the important areas of the speech that follow. This helps prepare the listener for what's ahead. It also helps to frame your most important points clearly in the listener's mind.