MicrostockGroup

For sure, here is the explanation : SS only have blonds in their customer base 

I know, buyers are present simultaneously at more agencies. I just buy some magazines to see what stock is printed there and I see constantly 2-3 agencies on the edge of the page. But the common thing I see is the names, shutterstock and istock almost everywhere.

We know, the customer's articles, blogs, magazines, etc. will be illustrated ANYWAY, but for an agency it's not just the same, where the customers buy the images.

The difference maker? It's the agency. The customer anyway will buy an image, so let's make them to buy from us!

Can we say that the customer base can be seen in the mirror of the agency? Let's think about how an agency treats us, photographers, so this way treats customers too, because they can't be different with the customers. We say what are our problems, but I'm not sure the customers will say too... They want to change something, or they just want to illustrate their articles?

@icefront: I think that contributors are just suppliers of the goods and only buyers are really customers for agencies. Supplier is nowadays overabundant resource so agencies can focus mostly on fighting for customers. So I do not agree that customers are treated like contributors cause agencies would start loosing them.

@RT: Interesting analogy, unfortunately everybody  is going this way with introduction of subs on almost any major site.