Just like Xbox in my previous post I will tell you here a secret method to get iTunes credit for free. You dont need any membership like Xbox at itunes store but you need credit to purchase the premium content.
As the title say above here I will tell you how to get that premium content on itunes store for free. All you have to do visit this itunes code generator and generate a code. After generating code complete a survey to get the last 4 digits of the code. You can then use that code to add credit to your itunes account for free. Later this credit can be used for purchasing premium apps or music or whatever you want at itunes store. Subscribe for more such tricks.