Silverlight as a technology is similar in intent to, and a competitor of, Adobe Flash. It is used for advertising as well as other purposes, such as browser-based games and video streaming.
The article specifically indicates that "Silverlight-powered media on Xbox will have the same appearance as ads seen on a Web browser."
Video rental service Netflix recently began using Silverlight for web-based streaming, and MediaPost says Microsoft will also use the technology to add more and better-quality video streaming options to Xbox 360.
With the move, Microsoft is aiming to make advertising available across personal computers, consoles, mobile phones, and even devices based on Microsoft Surface, with a minimum of redevelopment necessary between platforms.