I don't track each photo, but group things into sets. Each set has about 15-20 images. I use seperate sets for photos and illustrations/30 work. Once I have submitted a set to an agency, I mark it as done. As far as tracking income per photo, each agency has some way of doing this, but I found it very time consuming when I reached 700 ish images to look to much.
To me I find two peices of information critical:
1) What flavor (or type) of my images are selling best overall
2) What flavor is selling best within the last month.
I finding that by focusing my efforts not groups or types of images that are working well, I can actually have some time to produce more photos, rather than starring at the numbers.
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