Game delivery has followed this trend and made a number of advances o in the past few years. Rather than purchasing games on CD or DVD customers now have access to direct downloads from retailers as well as online services so that the games can be had without ever leaving their home. All it takes to do this is a broadband connection and a credit card, so for most gamers, things could not be easier. The most successful implementation of this has been Steam, the service from Valve Software. This system exploded in popularity because it is the best way to get access to Half Life 2, as well as play Counter Strike: Source and Day of Defeat: Source online.