The smaller papers rely more on single copy sales than the majors, obviously, because they have no subscriber base.
Still, single copy sales - in corner stores and boxes - figure into the equation at all levels. Blame it on USA Today when they launched, in the early 1980's, with their flashy boxes - the competition was forced to upgrade their street presence too.
The days of the honour system - when you dropped money into the box and took a newspaper from the open pile - disappeared years ago, though I remember it in the 1980's.
The internet, and the spreading rash of free newspapers, is having a huge effect. You can't turn a corner downtown without meeting someone in a suit handing out a Globe, enter a No Frills without having a Star thrust at you, or venture onto a campus without finding piles of newspapers. Colleges and universities themselves now churn out massive numbers of student publications, a niche for each college on campus. The market for print publications is competitive, cluttered and overlapping.
Tidying up Toronto's streetscape by introducing multiple-newspaper vending boxes doesn't mean we restrict the freedom of the press, though it does mean someone has to decide which papers are worthy of a place within - and which are renegade publications that must survive as best they can without.