I found a thread on DP Review forum where someone asked the same question, and the answer appears to be yes, the shutter count includes electronic shutter. But if you send the camera in for service, they should be able to report on the actual number of mechanical shutter actuations. Meanwhile, keep on shooting and having fun! 3900 frames is a good morning for sure. Out of curiosity, are you using C-RAW? I've switched to that to take advantage of the file size reduction (about 2/3 the size). It's quite handy for people like me who lean heavily on the shutter button. Everything I've seen indicates that there is no loss in quality at all.