The problem with this story is that the thing that made it interesting came all the way in the end. That's more acceptable in a flash story - being uninterested for 2 minutes before payoff is not as bad as being uninterested for 30 minutes before payoff. But still, the ending, while good, is not quite enough to justify it in my opinion.
This is really a flaw of the medium - in print, this story reads a lot better as reading for oneself is a lot faster than being read out loud to, getting to the clever twist earlier.