while the 10% number of lost sales might be correct, there's one more thing you should factor into the calculation: The cost you need to pay for these 90% illeg

while the 10% number of lost sales might be correct, there's one more thing you should factor into the calculation: The cost you need to pay for these 90% illegitimate users. There's support cost (some pirates are for sure dumb enough to call/email support even though they didn't pay), then there's the cost of infrastructure. Depending on the type of your game this can just be hosting a high score list or much more on the server side. So depending on your game, a pirate isn't just lost revenue but it will actually cost you some amount of money - in some cases a significant one. In reverse, that means that honest players are in a way paying for the pirates as the developer of the game has to ask honest players for enough money to run the infrastructure for everyone - including the pirates.