Hello guys, I'm new here and if you do not mind I would like to ask some things. Recently I made a Steam account because I want to play Modern Warfare 3 and later Call of Duty Ghosts, but I do not know exactly how to use Steam, because until now I was playing in fourdeltaoni. So my question is, you need to buy the game through the Steam store so I can play it, or I can buy it from a store that sells video games? If you can buy it from a store, what should I do so I can play the Multiplayer via Steam; Thanks again guys. Greetings from Greece.