Every form submission, in the person's own words, with where they came from. Label each one so tests are judged on good leads, not just more leads.
“Got your name from a neighbour. Can someone come look at sod and irrigation this week? Evenings work best.”
“Insurance adjuster already approved the claim, just need a contractor for a backyard design.”
The AI labels every lead. “Needs review” means it was unsure, so a person decides; anyone can change any label. The AI reads the answers only, never names, emails or phone numbers.