When speaking to a very small group of people you should be able to include an extremely large amount of customization. You should have researched the group and done your normal homework including phone interviews with the expected attendees (if it is a public event and you don't know who is coming, be set up way early so you can greet and interview people as they arrive.) Jot down a note of why each person attended. Then, when a section of your talk applies to them, point it out and name them by name.
Example: "John, you told me you wanted to learn how to sell more to the people that visit your website. This section specifically addresses that, especially the part about the psychology of the sale.
"Don't assume that people will perk up when you come to the part that specifically applies to them. Make a big deal to point it out to them. You will be adding an extreme amount of value which makes them realize that it was a good thing they attended. Oh and don't forget they'll love you for it.