As of 2015, the only legal way to obtain unused Xbox Live activation codes is to purchase them through a retailer, such as Best Buy, Gamestop and Amazon.com, or from the official Xbox website. Many sites claiming to offer free codes pose a security threat to users.
Xbox Live serves as the online component of Microsoft's line of home video game consoles and enables players to access digital content through the console and purchase games in its digital store. To play games online and use certain special services, owners need to have a paid Xbox Live Gold subscription. Players can activate such a subscription by purchasing a membership activation code and then entering the code into the account on the console. These codes provide a subscription to the service for a set period of time, typically either three months or 12 months.
Many sites claim to offer free Xbox Live codes to a member that enters his Xbox account information. However, these sites use the allure of a free subscription as a means of phishing for personal information and hijacking player accounts. According to the Account Security page of Xbox.com, players should never share account information with any website or third party asking for it.