for me, I count on:
1 in 1000 to be "gallery" shots I'd have no shame putting a hefty price tag on.
1 in 500 to be "printable" shots that would be like $15 dollar matted prints.
1 in 100 to be "keepable" shots that I might put up in my bedroom.
all the rest are JUNK. BTW, these numbers dont count shots of vacations, friends, family fun... these numbers are for my professional hopes of selling prints. Lord knows I've got over a thousand shots of my girlfriend I'll never get rid of.
this means if I wanted to have a booth at next springs Art Festival with 25 prints for sale, I have to shoot at least 25,000 shots in the next 8 months =D. I can do it. And so can you!