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In my opinion, there shouldn't be any fear about the piracy. When we talk about AppStore particularly, every app you see in there is sooner or later pirated and unless you create the next number one hit on AppStore, people will not rush to buy you software (in that case, it'll be probably cracked in a day or two after the release).
Our game, "FastBall 2", had been cracked the next day that it's released. I had seen enormous amount of increase on online leaderboards and after a while, all the new crack momentum went away. And even this, it end up in "New & Noteworthy Section", sold well and still sells a good amount.
In short, no need to worry about this matter much and just try to create a very enjoyable game which can reach a wide audiance...