Common - probably not. We put one in (NC - Eastern windows) and we never use it. As you said, it is pretty cool on its own. I don't run the a/c down there and it is always a few degrees cooler than the main floor. When you are at the windows at the right time of day, it is a little warm but that area isn't even covered by the ceiling fan.

My 6 yr old house has a walk out basement with lots of south light. We put ceiling fans in two bedrooms, a large family room, and the exercise room. All of these rooms have a lot of light.

I like ceiling fans. I have them in many rooms on the main level as well. I wish I had one in my master bathroom.

We are in Central/southern Illinois and are experiencing a heat wave and drought.

We are in the northeast and our walkout maintains a temp of 63 all winter without heat and will warm up to about 78 on the hottest summer days if we keep it closed up, so we didn't put in ceiling fans. (personally I'm not a fan of how most of them look.)

You could put in provision and then wait to see how the place performs and add them later if need be.