Did you put out the leaflets through 10000 different doors? I find that when doing flyers you are best to pick an area and do it over several times with a few weeks between each leaflet drop, I gaurantee that every time someone will say "I was meaning to call you last time" or "I've been looking for a window cleaner everywhere".
There is no problem picking up work this time of year, I have just picked up 6 houses in 3 days without even looking, the work is out there, just target a specific area, perhaps have a walk around first and see how many houses have dirty windows, then if there are alot really hit the estate with leaflets over a six or nine week period, it will work even better if a window cleaner has leafleted a few days before you.
marc