hi, 

Inspired by a thread in the shutterstock forum I calculated my �download density factor�.
But I never heard before about this index. 
The download density factor is calculated this way:

(all time # of downloads/# of months of membership)X (1/# total # of your images)

for example, you have
-50 images
-50 downloads
-been a member for 1 month,
then your IDD factor is:
(50/1).(1/50)= 1, which means, on average, you get one download per image per month.

another example
-22 images
-500 downloads
-member for 5 months
then your IDD=(500/5).(1/22)= 4.54 which is superb (ie, you are getting 4.54 downloads per image per month off your gallary)
the higher your IDD, the more popular you are.
notice that this number will change over time. If it continues to rise, you are improving, if it starts to go down, you need to start thinking of new strategies/better quality pictures

Since I never heard about this factor, I would like to know your opinion. 
What exactly does it measure? 
What are the pros? What the cons? 
 What is your download density factor?   

by the way.... may factor at SS ist 0.83 

Thanks,
gunnar

It will also make a huge difference how many images you started off with.   If you had a portfolio ready to upload to SS then your factor would be high from the beginning giving you a high average factor.  If you started off from stratch and gradually built up a portfolio your average will be much lower.
My factor is 1.69 at SS. I started off with 200 images in the first few weeks there and have gradually worked up to over a 1000.