I sell hummingbirds, mostly high speed flash photography, which has a different look from natural light. The main advantage of that style is that it shows a lot of detail not seen as well in natural light photos. And it sells relatively well, compared to most critters. I also sell some iconic scenery from major National Parks, mainly in the southwest. I didn't choose these subjects for the marketability, I chose them because personally, they are a concentrated beauty showing my best experiences in nature. The fact that hummingbirds trigger our "cutness" receptors, making them salable is merely a happy accident. There is lots of competition for hummingbirds and National Park scenery. For example, I've sold some good size prints of a stitched panorama at Tunnel View in Yosemite, showing El Capitain, Half Dome, Bridal Veil falls (with mist rainbow) and points between and at the extremes. Perhaps millions have taken these shots, and thousands as a stitched panorama. But it is so beautiful, that i was able to get a tiny fragment of that market. I would like to think that my love of that location helped me create an image there, from spending hours there on several days on several expeditions (I live in Georgia.) For me, the main profit is simply the honor of being there on those occasions. And of course, the other experiences in my sojourns there. If I never actually sold a print, these are experiences I have been extremely fortunate to have been able to seek out such natural creations. The chance to make a little art, and to make a few sales is the icing on the cake, and the sprinkles on the icing. So I'll add a rattlesnake found on the periphery of the highway at a sea lion beach on the start of the "good part" of CA highway 1, for example, because who knows who will like it, Or a photo of the pet cemetery at the "best friends" animal sanctuary, because somebody will have also have sentimental connections to that beautiful facility, and their important work. So if you like it enough to photograph it, include images into your portfolio, perhaps in an "experimental" gallery if you are not sure if it fits in well with the main body of your work. But I'm not one that seeks to concentrate on a style, but what I seek is the appreciation and enjoyment that I discover, using whatever technique and style I can muster.