Hmmm... Let's see.
Before I begin, let me say that my answers refer to more selective stock agencies than the micro-payment agencies typically are.
Pros: - Offer a way to market your work to clients you may never have access to
- If you have a good collection of images, you can make a decent and steady monthly income
- Makes you learn about trends and what kinds of images sell
- If you are with a good, agreesive agency, they can still find markets willing to pay good money for quality images
Cons - Unless you have pictures of aliens or Sasquatch, you have to have a TON of quality images on file at the agency to make much money
- Takes time to prepare images and keyword them to the agencies specs.
- Your images are competing against other photographers in the agency for exposure
- Takes a bit of time to keep up with graphic design trends
The stock business takes a lot of images and a lot of variety of images. I think people with a specialty do better than people with general images. Right now the market is flooded with the general imagery that you see in the micro-payment agency sites.
With what I do, I am not getting rich by any means but the checks I do get from the two agencies I work with every month are a nice little addition to the bank account.
In addition to the agencies I deal with, I am also an agency of one. At
russellgraves.com, I represent Russell Graves and that stock agency performs better for me than do the other ones.
Good stock photography, in the end, takes research. Learning to spot visual trends and then capitalizing on them with diverse and creative imagery can make you some money if you get accepted by an agency.
I hope that helps.
-Russell