Ask at the moment of need, derive what you can, and delete the 'nice to know' — field count is the strongest completion predictor, and marketing's wishlist is conversion's tax.
Immediate per-field feedback, errors stating the fix ('add an area code'), and never clearing the user's work — the error-summary-at-top pattern is where completions go to die.
Logical steps with real progress indication, save-and-resume for anything past five minutes, and review-before-submit for consequential submissions — multi-step wizards that respect the user's time investment.
Field-level abandonment analytics name the exact toll booth losing you customers — conversion optimization is instrumented deletion, not aesthetic debate.
Skipping the discipline this article describes until an incident, audit, or stalled project forces it — every practice above is cheaper adopted early than retrofitted under pressure.
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