Q: It costs $100 for the little piece of plastic and I want to know why I need it to play online. I have internet connection already, and a gold membership account, why do i need a wireless adapter to play online?
A: if you already have an internet connection available to you then it's now a matter of connecting your Xbox to it. The procedure for doing this will depend on what sort of device you use: if you're using a router or similar device it's usually just a matter of plugging one end of a network cable into a spare port into your router and the other end into the Xbox itself. If you're using a USB modem-type device connected directly to a PC then you'll have to configure internet connection sharing software on the PC and connect your Xbox to it.