One of the oddest aspects of live performance is the end of a comedian's set. The end of a theatrical or a musical performance is usually very obvious. Climactic even. The audience shows its appreciation and there may well be an encore or a curtain call.
In comedy, the performer tells a final joke and that's it. You don't really know it's the last joke until they say "thank you and good night". And is there anything more incongruous than a comedy encore? The performers who've thought this through are few and far between, they stand out a mile and they tend to be the best performers anyway.
The way you take your leave of your audience is much under-rated. First impressions are important, but so are last ones. Is your audience's last impression one of resisting unwanted up selling offers, one of indifference as you look for the next prospect or one of unsatisfied needs that leave them in the same position they were when you strove to make that first impression?
Or is it something that cleanly ends the encounter in a way that leaves them eager for an encore?