The clerks behind the deli counter serve customers according to the numbers on the little tickets that everybody picks up when they arrive at the deli. This is the same system that is used at 10,000 other delis.
I'm holding number "9". The 50-ish year-old woman standing next to me is holding the number "8". The clerks at the deli are now helping the customer with the number "7".
Eventually, customer #7 gets what they want. So, now it's time for the next number. One of the clerks says in a loud voice "who's next?". There is an awkward pause and then I hear one of the clerks ask in a loud voice "who is next -- what is the number after '7'?" Me and the 50-ish year-old woman look at each other quizzically. After a second she suggests to the clerk that eight is the number after seven, at which point in time the clerk says "Yeah, that's it! Eight is the next number. Who has number eight?". Me and customer #8 exchange a knowing look.
Eventually, customer #8 gets her Polish ham (sliced medium), and I get my pastrami (sliced thin). When I get home, my wife notices that I didn't actually get the pastrami that I asked for ("thin and trim") but instead got some other kind. Customer #8 seemed to be a much more savvy shopper than I was -- I'll bet she managed to get what she asked for.
I think that Beavis and Butthead summed up this situation nicely:
[a teacher asks Butt-head if he is angry for some reason]
Butt-head: Uhhhh... I'm, like, angry at numbers.
Beavis: Yeah, there's like, too many of them and stuff.