In-Game Texture2D Banner Ads?

Does anyone know of anybody successfully implementing in game banner ads in their 3D world for monetization purposes?

I’m working on a new game and I like the idea of getting a JPG from an ad network that I can then render into the game world as a new Texture2D on the fly.

What do you think? BTW, I’d be putting these in areas that gamers could slow down and take the time to look at (i.e. the game isn’t a FPS).

Just load an image into the texture2d using the WWW class.

I guess the question I’m really after is, what ad network supports loading a JPEG and is smart enough to credit your account for the Ad Impression, while also not sending you something that won’t go into a Texture2D like flash content.