In the future, as the world becomes bought by multinational corporations, and the only thing more valuable than water and personal space is the idea of a person's free time, the obscenely wealthy will pay astronomical sums to have a surgical procedure which alters the receptors in their brains, so that all advertising is filtered out. You can buy back your eyes, so to speak.
Companies then subsidize these operations for the middle-class, on the condition that they allow only ads for their particular brand to be processed. Susan, for example, sees only Coca-Cola ads. Jonathan only sees the bloated, freckled face of the now-resurrected Bob's Big Boy. And there are millions of "Archies," the lowest social class, whose brains have been bought by McDonald's.