Reminds me of this Futurama scene:
[Fry and Leela after Fry had an advertisement in his dream]
Leela: Didn't you have ads in the 21st century?"
Fry: Well sure, but not in our dreams. Only on TV and radio, and in magazines, and movies, and at ball games... and on buses and milk cartons and t-shirts, and bananas and written on the sky. But not in dreams, no siree.
If this technology gets refined, this might even be a reality in what, 50 years?