I'll submit one more.
Homework - the continuous study of the art and science of our craft. Whether it be product research, split-testing sales copy, market research, self-development, whatever. It's my own opinion that you can never have enough information.
P - prospect
A - attention
I - interest
D - desire
C - conclusion
A - action
S - satisfaction
H - homework
PAIDCASH - you'll see this formula in a book I write someday!
Ok, I'm just kidding. Gordon and Andrew do add great points - gotta admit PAIDCASH would make a great copywriting acronym though.