Malvoisin said:
First, I want to point out that past experiences can not be 'nullified' but they can be counterbalanced.
Depending on how a game ends - especially if it peters out and then people start to abandon it without saying anything - the game could cause negative experiences as well as fun.
Frustration at the uncertainty can be bad, because you never really know if a person is just being a slow poster or has abandoned the game. Seeing someone who has abandoned your game still playing in another game can create feelings of betrayal (since you know it's not just a case of real life busyness), especially if you thought you had a good rapport going on. If the game drags on half-dead as some players abandon it or slow down, you still have to check it and it prevents you from joining other games unless you foolishly don't care if you overextend. If you get too frustrated, you might abandon PBP games altogether.
If all this can be avoided by choosing shorter modules to begin with, why not try that?
Creamsteak - the players and DM may not be well informed about the odds.
All that said, if you think the game could be really good, go ahead and play it! The point is that more short games should be tried by more people; of course there is still room for longer adventure paths, but that should be the exception.
To put it bluntly, I am trying to make a point, and admitting the exceptions to that point, while more accurate, is not so conducive to persuading people that my point is basically correct. One reason is that people have a tendancy to say "If what I have been wanting is possible at all - then that's the only thing that matters! It might as well be a certainty to happen! Forget the idea of other options that may be more practical!"
