Simple answer: You receive an offer!
Even before the multiple offer frenzy of 2020 the rule of 10/10 applied. If a property is priced right it should receive an offer within 10 days of being listed or within 10 showings taking place.
If the listing has been on the market for more than 10 days or has had 10 showings and you have not received an offer then the mark was missed. This can be remedied by adjusting the list price… the key is to adjust quickly so the listing stays relevant in the market.