Yeah, I think it has to do with what time the people who have you added to their faves are generally on. I have mainly always done evenings and nights, and so I am pretty busy those times. Because those are the times the guys who have me on their faves list, are online. I switched to more of a day schedule, last Summer, and was not as busy as I expected (at least right away), because I then had to make new day regulars. So whatever schedule a person keeps, they will build up regulars for. I always thought there was no point to real late nights, but I have been real busy recently, late nights on SM. Likely down to there being a lot less people on to compete with, as whataman noted. When I work late nights I always make a ton of new English and Australian contacts. It's kind of fun.
I actually found it stressful when I switched to days. I felt that I let a lot of my regulars down, because they would ask where I went. Then when I went back to nights, same thing happened with the day regulars I had built up.