Recently, I tried doing it. No tricks, no magic, just clicking my fingers over a lighter that had failed to light previously. And it worked. It has worked on all but one occasion out of a possible 20 times or so, and on that occasion, I used my off-hand, rather than the hand that had been attempting to catch the spark up until now.
So now I'm completely baffled. I don't know why it works, I have no clues or suspicions at all. Does anyone actually know the physical reason why this trick works?