I helped my friends pirate the first 10 audiobooks of a series I love, by handing them a flash drive with the MP3s on it, and the condition that if they liked the series they should buy the new ones as they come out.

Now 6 of my friends (who never would have been hooked on the series otherwise) own legal versions of the two most recent novels starring our favorite wizard-detective.

Those sales would not have been made if they hadn't gotten a taste of the series beforehand. Sure, this situation isn't the rule, and they pirated 5x the books they've purchased... but 2 sales each is better than 0, and with 8-10 more books coming in the series, the author/publisher have come out far ahead.