Crossed 1MM a few hours ago flying LAX-MEL (thankfully, in J). Was recognized and thanked by FAs on LAX-MEL (who were also generally spectacular throughout), and was also greeted and thanked on SFO-LAX immediately prior, both of which were nice touches – didn't preannounce or really mention to any staff except in passing at boarding on LAX-MEL, so was pleased.
By total coincidence, the calendar date in US time that I hit 1MM coincided exactly with the fifth anniversary of my first flight on UA, which was a nice (and, I'd stress, unintentional!) touch.