RIAA doesn't like it, but my introduction to a video game series I've since spent hundreds of dollars on over the years, came from running across one of its soundtrack pieces on Youtube.

There's a reason companies talk about "customer acquistion cost", as you generally need to pay to market your products to potential customers of them.

So free marketing can be a real cost reduction. It may not be enough to be a benefit compared to the cost of piracy, but it's hardly a made-up defense.