
Ask about the past, not the future: "When did you last try to fix this? What did you spend?" Treat every "I'd pay €X" as at least 20% too high. Count only real commitments (a pre-order, a deposit, a booked call), and set your stop rule before you ask.
S Evidence: strong. Large trials or many studies, pointing the same way.
Schmidt & Bijmolt 2020 (77 studies) · Webb & Sheeran 2006 (47 experiments) · The Mom Test (practitioner).
Not medical, legal or financial advice.
In The Ecosystem every framework comes with a daily action, a room that checks in, and the full library.