I have. From August 2007 to November 2007 I picked up 170 customers through leafletting alone. It was the 'put in window' style leaflet, not the 'ring me when you can be bothered' leaflet though. I now have nearly 300 and still continue to pick them up. Got a £12.00 today in fact.
I posted 1000 of the latter leaflet in the beginning and didn't hear a dickybird.