A compelling story beats a mountain of facts every time. Stories don't have to be amazing, incredible tales—often family mishaps and personal insights are very moving. Author Sue Miller stated in a 1999 New York Times article that "...you can make a story out of anything, anything at all. What's hard—and what's interesting—about a story is not so much the thing that's in it, but what's made of that thing."
Like any powerful tool, however, support can be overused and misused. The PEP formula ensures that your speech doesn't become a string of stories; support devices should bolster your main points, not vice versa.
Make sure your supporting examples and quotes are well rehearsed, accurate, and tie into your purpose. It's tempting to plunge ahead with a lively story or fact without checking it thoroughly; after all, no one is going to write down every word you say, and you are just trying to keep people interested. But in any field or endeavor, mistakes can come back to haunt you. The best speakers use accurate data, accepted definitions, and good sources. Finding authorities on your subject may take a little extra research, but it's worth it.