In your conversations with people, one of your key objectives is to keep their attention. Only when their attention is locked into your conversation do you stand a chance of building rapport and taking things where you'd like them to go. The best way to keep someone's attention is to generate their curiosity or interest in what you are saying. Curiosity and interest can, of course, be built through the tonality that we use, but one of the best ways to do this is by talking in terms of either stories or interesting facts. Also, talking about unusual facts that are relevant to the situation can engage people more and help to create that element of curiosity and interest in what you are saying.