In the field of robotics there's an idea called the Uncanny Valley
. The idea is that people prefer robots that look more like humans, but only to a point. Once they resemble humans very closely, but not exactly, they start to freak people out.
In architectural photography, this feels somewhat analogous to the situation with straightening verticals (keystone correction). When people view images that aren't corrected, they intuitively know that the home looks funny. In most cases they don't even know why, but they can sense it.
Once the image is corrected, though, it suddenly feels much better.
I have posted a tutorial page on keystone correction
in our resources
section. I encourage everyone to learn this technique and use it to improve your quality and expand your business with this value-added post-production service.