I'm lazy most of the times, I don't bother cleaning unless it's been 500 or more rounds. I have two reasons besides being lazy though.
1. I like to know my pistol actual will run in an adverse state. I feel a pistol that cannot run reliably for a MININUM of 1000 rounds without maintenance is a sub-par pistol. There are too many pistols that can do this, but until you try, you don't know if you might have a "lemon" or not. Better safe than sorry.
2. I have multiple pistols of the same platform (Glock, M&P, 1911, whatever) and would use one for range use and the other for CCW. Being they would have the same operations and feel, I could carry the clean one while using the other. Once I got to a certain point, usually 1000-1500 rounds, I'd switch them around and repeat the process.