Many of you know I am a Jehovahs Witness, and I knock on lots of doors and rejection/apathy doesnt bother me too much, and some of that may be because we usually work in 2's (what Matt suggested).
but knocking on doors selling a product did bother me.
I did it about 20 years ago selling domestic fire alarms. I did it but not for long - it was soul destroying. There you are with the best alarm system for its price :
and no one wants it.
One thing I did learn on a course was....
even if you went to a door with a negative opener like "I dont suppose YOU would be interested in a fire alarm system", I was told stastistics say 1 in a hundred will say "yes".
Now subsititute "having your carpets cleaned" and you got a chance of getting 1% success rate.
and dont forget some of the other 99 will be not at homes, and others not interested, so you leave a leaflet from which you may pick up another 1 or 2.
Might try it myself again.