A company that sells pictures, makes sure that they have visually stunning images that can illustrate the most weird and wonderful subjects. Take a subject like dyslexia; how to illustrate this? A friend send me this wonderful example of a photoshopped picture that does this really well.
When you read the Wikipedia article, there is no illustration. This is where visually stunning pictures that express the issue are needed because this article is factually correct, it is hard reading with the key facts hidden behind all kinds of classification.
Stock photography is about illustrations. When there are many pictures that illustrate a subject, it is indeed the most visually attractive picture that will be sold. When you seek an illustration, you will find that historic pictures are an important part of a collection. They are because they provide a view that is no longer there.
With the arrival of sharing options at Commons, we have the opportunity to strengthen its stock functionality. With over 270 Wikipedias our own need for multiple pictures for one subject is intrinsically high.
Commons is slowly becoming a stable source of freely licensed pictures. We have the opportunity to make it the "goto" place for quality illustrations. With 7,626,589 freely usable media files, the basis for such a function exists. What is left is profiling and marketing us as a source for great illustrations.