"There is a big difference between what is now known as "piracy" and stealing. Stealing does constitute a direct loss of sales for a company. Stealing entails physically going to a store, taking something off a shelf, and walking out of the store without paying for it. In doing so, the thief takes tangible goods out of the store. It cost the company something to manufacture the packaging, to burn the CD, and to ship it to the store. Furthermore, the removal of that item from the store's shelf means that another potential customer may come in and find the shelf empty, in which case that potential customer will be unable to buy the product. The result of this is that the customer may end up buying a different product simply because the store was sold out of the original item. In this case, the thief has a direct, tangible effect on the revenues of a company.
Piracy is a totally different thing. With piracy, the pirate sits in his chair at his computer, looks on file sharing services for a copy of the full version of the software, and usually waits a few hours for it to download. It's true that the pirate is getting goods without paying for them, and that it's a morally unacceptable action. But that doesn't mean that he cost the company any money.
See, when a pirate downloads a full version of a piece of software, the pirate isn't leeching bandwidth from the company's servers. The pirate has to download the software from some other person who has already purchased it. So bandwidth costs because of the pirate are zero for the company. Furthermore, the pirate isn't depriving any other potential customer of the game: he has not physically removed a copy of the software from a store shelf. There's no loss of sale for the company there, either. Finally, the software company paid absolutely nothing for the packaging or manufacturing of the product. Given the nature of computer software, it was downloaded from someone else's computer; so no manufacturing was needed.
It could be argued that piracy amounts to lost sales because a pirate would be motivated to buy the software if he couldn't download it. However, given that pirates go out of their way to search the internet for pirated copies and to wait for the software to finish downloading, it's still highly unlikely that they would have ever bought the software, whatever the circumstances. Pirates don't want to go to the store, and they don't want to pay money for software. So this can't be legitimately construed as a loss of revenue."
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