If you're lucky, you can find codes on the web for free, on blogs or forums.
Check out --> http://winfreeitunescodes.info for free Free Itunes Codes.
Since the launch of iTunes, came the itunes codes. These are esentially vouchers which enable a user to redeem the itunes service on their account, free of charge. However, these might not be as easy to find as the average redemtion voucher. The aim of the itunes code was to allow people to buy itunes as a gift for people. They could buy the code from Itunes, and either print it out of email it to their friends or family to be given as a gift. Sites such as the Carphone warehouse give out itunes codes and accounts for free, but that is with the purchase of a phone contract.
With iTunes in the Cloud, the music, apps, and books you purchase automatically appear on all your devices. Or you can download only the stuff you want — including movies and TV shows — to just the devices you want.1 It’s all part of iCloud and iTunes 10.6.
