In some cases, nothing! The best part of a joke comes (wait for it…) at the end. However, the best part of a demo should be presented in the first few minutes (within 6 minutes, in the best cases). Those who “save the best for last“ suffer from exhausted audiences (who are too tired to appreciate the best part), reduced audiences (the highest ranking customers have likely left the room), and running out of time (“Sorry, we didn’t have time to show you our reporting capabilities – our best stuff – but trust me, they’re really great…”).
So, if you want your demo to be perceived as a (sad) joke, save the best for last…!