I live in a town of about 43,000 people in the suburbs; have lived here for about 7 years. In all this time, have had them at my door about 4 times.
Interestingly, have never seen them on my street or any other nearby street here. The reason for this, I think, is what some have hinted already, i.e., they seem to have adopted the hit and run strategy. This door-to-door work is so inefficient that they know that after the first door, there is no way to have someone else open the door to them.
That's why it is so much easier to find them at the Dunkin Donuts shops in the area than anywhere else. So, no matter what time they start or stop the work, 2 hours will always go down in the slip. It's a complete sham.
This, of course, creates another situation that is absolutely ridiculous but one that I have seen more than once: publishers returning tons of publicactions to the elders/counter, instead of tossing them in the trash bin.
Observador.