I do think that reps may inadvertently help boost product awareness; not because they're reps, but because they are mistaken as gen. If someone happens to catch a glimpse of the watch on your wrist and it's perceived as a genuine, that may or may not influence someone's decision to buy the same watch. If they only know what they see (i.e. they are not an expert in identifying or discerning the difference between a genuine and a replica), then there's no way to really acredit that purchase of a gen to replicas directly.
I do agree that potential lost sales or decreased market share are likely enough of a concern for a business to take appropriate action. However, the focus of attack is probably done at the source of production or distribution, and less concentrated at the level of consumer due to volume. It would be extremely difficult to hit each individual buyer, but at the dist or production level, it's a little easier to target for aggregation. And also a fair bit more transparent to us, the end user...