Laypeople really don't seem to care about Three Fly. They get confused.
That is the dichotomy of magic. There are so many cool and impossible effects we can do, but performed without proper motivation, may lead to just confuse our audiences.
In some cases, we actually have to TELL our audiences EXACTLY what we are going to do, for them to be able to form an explanation of what it was we actually have done.
Three Fly is one of the most obvious examples for that. Simply performed by itself, will not get much of a reaction. The effect is over, and your audience still isn't sure what it was they had seen.
Matrix/Chink-a-Chink is another good example. I remember watching David Roth perform for Letterman. Wow. I thought his performance was pretty dry. As with most coin magic I see. An entire minute of explaining the different ways the coins can be covered with his hands, and what can be done to the coins, etc. Before he spends his 10 seconds of the actual effect.
Makes me ask myself, if all of that has to go down before you display a very visual effect, is it really magical?