Still coming? prompt
A Still coming? prompt is a check sent to a waiting customer to confirm they are still on their way, so people who left do not clog the line.
Also called: are you still coming, line confirmation, still here check
Virtual lines have a weakness. A customer can join, change their mind, and never tell you. Their name stays in the list, adds time to everyone behind them, and eventually gets called with no one answering. Over a day, those phantom entries make the quoted wait look worse than it is.
The prompt is a cheap fix. After a person has waited a long time, ask whether they still want their place. A tap says yes and keeps them in. No answer past a reasonable limit, and the spot is released.
Timing is the trade-off. Ask too early and you annoy people who are happily waiting. Ask too late and the ghosts do their damage. Setting the check relative to the longest wait you tolerate keeps both sides in balance.
How NextUp Walk-in handles it
With check on long waits turned on, a customer who has waited about three quarters of your limit sees a still here check on their status page. Confirming resets their clock. If they do not answer and pass the limit plus a 30 minute grace period, they are removed from the line.
Questions
Why remove people who do not respond?
Stale entries add time to every wait quoted behind them. Removing them keeps the line and the estimate accurate.