I'm running into a mental block here. I've read the Wikipedia entry on it, but still. What exactly makes a commercial photographer? It's not the subject matter. Is it the client? I mean, say you shoot an environmental portrait of your friend, who happens to be a snowboarder. That's a portrait. But say then that Burton Snowboards sees that photo in your portfolio and wants to use it in an ad. Does that now categorize that photo as 'commercial'? So, ostensibly then, if you were to market yourself as a 'commercial photographer', you could have a variety of images from portraits, to sports, to interiors, to products, to scenery - virtually anything? The underlying connection between all of them is that you're taking these photos with the intent for commercial usage and distribution?