I know my view might be an over-simplification but in general QRP sucess is dependant on NOT getting run
over by big signals, and moving around and listening. Avoiding the 1 Khz "channels" tends to put you in a place
that others don't use and in a place where those tuning/listening for weaker signals are more likely to find you.
QRP enthusiasts, like the 4 States group, the Flying Pigs... seem to understand this very well and it is part of
why I enjoy participating in their events.
I offer, as a bit of evidence, for the 1 Khz channel theory, is that I routinely call CQ in between integer Khz frequencies
and I fairly often get a reply way off frequency and if I check, it's on the nearest whole Khz. In a few cases, the replying
station told me that I was off frequency.
It is an interesting phenomenom to me. Maybe, it's my early novice days where I'd call CQ and look +/- as much as
10 Khz for a reply because, back then, we novices were all rockbound. I was anxious for the day that I upgraded and
could spin a big knob on my radio and move to another frequency and not be stuck on a "channel" defined by the few
precious crystals I could afford as a kid.