The way I understand quantum suicide, it's supposed to force your future survival into the relatively scarce branches where an event goes the way you want it by making it dependent on that event. Killing yourself after living in the branch where that event did not go the way you wanted at some time in the past is just ordinary suicide; although there's certainly room for a new category along the lines of "counterfactual quantum suicide," or something.

edit: Although, to the extent that counterfactual quantum suicide would only occur to someone who'd heard of traditional, orthodox quantum suicide, the latter would be a memetic hazard.