There is only one cart set up where I live and it's the same siters every week.
The good news is I have not observed actual D2D witnessing in my area for a couple years now. It used to be that I could not leave the house and do errands without seeing a group of about 4-6 of them congregated on corners and going house to house, but I never see them anymore not even during "special campaign" months.
Not one, not a peep!
The lack of activity all seems to be since the introduction of the carts and the website.
This area was very visibly active a few ago, they prided themselves on it - not now though.