On the concept of pirated software helping to promote sales, I definitely think there is substance to this theory.
A few years back, during the period when the play station 1 was just out, a good friend of mine worked at a software house. He used to get promotional copies of software to give away, these used to be sent to shops and reviewers, etc. I always ended up with one. If it was a good game I would tell others, they would then go out and buy it.
In the days of the Amiga, even if 50% of the people I told went out and purchased the game and other 50% pirated it, this promotional copy still helped to make some sales.
Not pirating, but still free copies used for promotion.