Relevancy is the most important.

If your images pop up in searches for "flower", but your image is of a person you described as "cute as a flower", no one will buy the image based on that search and your image will be buried further and further down the search results, effectively becoming invisible.

If your image of an actual flower pops up and is bought when they search for flower your image will get stronger and stronger and keep its place high up in the results.

The hard thing is to nail the abstract, conceptual keywords. I have images that show up first in searches of certain concepts, concepts that could be shown in a thousand different ways - with animals, people, cars, simple illustrations etc.

But based on that search, many people bought those images meaning the abstract conceptual keyword proved to be relevant and the images stay on top for those keywords. Those conceptual keywords might not be the most obvious to think of when keywording, but illustrate the idea.

There is a lot of strategy and research tied to SEO. Photoshelter did an SEO primer a while back that I remember did a good job of covering the basics. That should give you enough to know where to dig deeper. Do a search for Photoshelter SEO.

Thank you

For your own website there are many things you can do to optimize your Google placement. Tagging images for other sites like SS or Fotolia is much less complicated. A few quick searches on each site will tell you how their search engines work.

There is a lot of strategy and research tied to SEO. Photoshelter did an SEO primer a while back that I remember did a good job of covering the basics. That should give you enough to know where to dig deeper. Do a search for Photoshelter SEO.

wow, i completely forgot they even existed after they closed their free agency.
how is Photoshelter in terms of selling indie btw??? is it worth paying for an account there???