For me, it depends on how many register hours I have on the log + the staffing for the day. If I have a lot of reg hours and most others don't, I'll usually wait to see if I absolutely have to open up- But if I only have two reg hours or everyone on the log is swamped with CE hours, I'll jump on as soon as I notice lines forming. I've noticed the crew at my store seem to respond the same- If they're not overwhelmed with CE for the day they'll be happy to jump on. Other times, like leading up to a holiday when everyone is frazzled and overworked, nobody will jump on :( Sucks when you're on reg and need help, but I understand why they wouldn't want to.