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.
“Can you give me free advice by email about my neighbour's fence?”
“Buying a house in Signal Hill, possession is the 30th. Need a lawyer for the closing.”
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.