Originally Posted by
Orion
The random feature covers two things: the random feature and malfunctions/mistakes. I have seen eight pax in a row rejected at DCA over not getting the beeps. Eight in a row is not likely to be random in my book. While I was in the adjacent line no one got the beeps for Pre.
It's not random based on the time you got in the Pre line. It's random based on other factors, and those eight people that weren't selected just happened to get in line around the same time.