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.
“Renovating the kitchen, need a 10x10 unit for about 3 months.”
“What are your gate hours? Just picking something up for a friend.”
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.