[Zeklandia]

You aren't free to ignore them. To even look at them to identify whether they are advertisements takes time. Even if it took a millisecond, with a billion people looking at it that's 12 days of man-hours lost on every advertisement.

Pamphlet distribution is peer-to-peer. People have to distribute them to other people. However, Advertising is usually lopsided: typically a group of people working together, like a magazine corporation, or a machine, like with Facebook, is distributing content to people. And again, receiving ads from these places is not voluntary. You cannot engage with the activity but refuse receiving advertisements, unlike my experience of walking around on university campuses and refusing pamphlets I am offered.