To me the most meaningful number is RPI per day.  For December, I'm at 11.4 cents per image, per day.  That's overall, as I don't calculate by the individual agencies.

I'm pleased with this, since this number has not wavered much since I began nearly three years ago.  When that number starts to drop, I'll know something is wrong... either I've hit the wall, my newer images aren't as popular as my older ones and I need to rethink my strategy, etc.

I track my RPI every month just because it is not difficult and my husband built it into my spreadsheet.  It's really more of a curiosity for me, than anything else.

I don't find it particularly useful, though, because it keeps changing with the size of my portfolio.  It isn't as simple as "My RPI is $1.5 per image so if I add 100 images I will make an additional $150". 

Gaja is close to a meaningful #, but the relative time to upload to a site should also be counted if you want to be really anal.

The important number is total $ in - total $ out and how much time you spent to get there.

If all you care about is RPD, then you are nuts to be in microstock.

If I wanted to boost RPD and RPI at DT, I could delete all my pictures below level 3, but that would probably be a stupid thing to do to my total income. In general my RPD and RPI have been going down and my total income has been going up across the board. I'd rather that than any sort of reverse of that.

That's why we differ in the reasoning and viewpoint. No problem, it's just different.

I want to know how much I earn for selling something. I don't care what I get for not selling something, because I know what that is. Nothing.

If it wasn't for the forums I'd be looking at what I earn per year from each agency and not on a by image basis. That's the kind of numbers I want, annual earnings, not bit by bit analysis. Some others want day to day and micro managing their numbers. Same as above. To each their own.

The problem with RPI is going from 500 images with a calculated RPI, and increasing to 1000 images, you don't get the same RPI for the second 500 images. And don't make double the money either. And using the same numbers adding another 500 images, it should add another equal amount as the first 500, but it doesn't. In other words, RPI is unpredictable and flexible, not a constant, and not really good for predicting future performance, only looking at what happened.

However I am swayed by louoates reasoning:

Total dollars earned in micro minus total dollar outflow for newest Photoshop version and newest digital camera and lenses. It you still have money left over you are doing very well. Merry Christmas all. My time would be wasted anyway, just like it is reading and writing for hours on the forum or playing Cafe World on Facebook. I won't count uploading and keywording time, which is my spare time. Somehow I think I'd be spending time and money, buying new equipment and software, even if I didn't do anything for Microstock.

Still using Elements 7 until they come up with the magic healing brush from CS5 in a version of Elements. That's cool!