When a longer line brings more sales

Downtown on Thursdays, once our line hits 12 people, Square shows our next-hour sales jump about 18% compared to when it stays under 6. Is there a food service term or bit of trivia for this social proof effect in QSR or food trucks, and has anyone used it deliberately without wrecking throughput?

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In QSR it’s “the line is the sign” — social proof/queue signaling (Social proof - Wikipedia). Cap the visible queue at about 8–10 with a short stanchion so it looks busy but bounded, and keep waits under 5 min with a handheld runner; past about 7 min the boost often reverses. What’s your ticket time once the line crosses 12?

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