How do you know there would be ads in the future? Maybe the populace got sick of their corp overlords and squashed the flood of advertisements on tv and everywhere else. Maybe it would be more of a gated community type of thing where political signs on your lawn and any class-less advertising pollution in public is outlawed. Or maybe the mass public would be so in debt, poor, or jobless that most advertising would be wasted on them.
Futurama episode where in the far future the character "Fry" is upset when he starts having dreams with advertising in them:
"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"