Key insights
- The mind keeps unfinished tasks in active memory and drops completed ones the moment they close — open loops keep pulling attention back.
- A progress meter stuck at 80% creates return pressure; a checklist shown as 100% done gives the user no reason to come back.
- In onboarding, deliberately leave one box unchecked — the visible gap nudges people to return and finish setup instead of vanishing.
- Profile-completion meters are the everyday version big platforms lean on: '80% done' becomes a persistent, low-friction pull.
- The effect only fires for outcomes the user actually wants — a fake 'reading progress' bar on a marketing email creates zero pull.
- Think of the mechanic as a loop: open it, let it pull, bring them back — open loop → pull → return.
Do / Don't
- Do: Leave a visible gap — an unchecked box or an 80%% meter — to invite users back
- Do: Tie the unfinished progress to an outcome the user genuinely cares about
- Do: Keep the remaining percentage salient so the open loop stays top of mind
- Don't: Close every loop at 100%% — a fully finished state removes any reason to return
- Don't: Manufacture progress on chores nobody asked for, like a reading bar on a marketing email
