Two dimensions, not one
Fit covers attributes that do not change with attention: industry, size, location, role, business model. It answers whether this contact could ever be a good customer. Behaviour covers what they have done: pages viewed, materials requested, emails replied to, messages sent, meetings attended. It answers whether something is happening now. Collapsing the two into a single score is the most common design error, because it allows a very engaged bad fit to outrank a quiet good one.
Thresholds and decay
A threshold should be set on both dimensions rather than on a total, and the behavioural half should decay. Interest is evidence about a moment; without decay, a contact who read three pages in March sits permanently above the line while somebody active this week queues behind them.
A worked scoring example (illustrative)
Score fit out of 10: correct industry 4, employee band 3, decision-making role 3. Score behaviour out of 10: pricing page visited 4, guide downloaded 2, email replied to 3, three or more sessions 2, webinar attended 3, capped at 10. Require at least 6 on each. A contact in the right industry and size band, but in a junior role, scores 7 on fit; if they visited pricing and replied to an email they score 7 on behaviour, and they qualify. A contact who downloaded four guides, attended a webinar and scored 10 on behaviour, but works in a different industry entirely, scores 3 on fit and does not qualify. The second case is where most single-score models fail, and the two-dimension version handles it without any special rule.