give it time ... should get a few...
customers can be a bit odd.
eg i put a load of flyers round this certain road, no calls, then followed it up with the odd door knock - got 3.
then when i did those 3 houses 2 more came out saying oh great a wc in our road please do ours, we can never find a window cleaner!
i know they had a flyer as i dropped them myself, one of these 2 i even spoke to when i door knocked!
most customers like to see you doing the surrounding neighbours windows before they will ask you...