“Decision” is the combination and optimisation of one or more model scores into a contact list. (Not to be confused with content recommendations, which is a separate recommender feature for your CMS.)
Why scores aren’t enough on their own
Ranking by a single score is a good start, but the best campaigns combine signals and account for cost:Combine signals
Multiply propensity × expected amount to rank by expected revenue, not just likelihood — a supporter who’ll probably give a little may be worth less than one who’ll possibly give a lot.
Account for cost
Every contact costs money. Past a point, mailing more people lowers profit. The decision finds where to stop.
What a decision does
Brings scores together
It pulls in the relevant model scores for your population — for example DM propensity plus expected amount.
Optimises the volume
Using a profit curve — expected income minus cost as you contact more people — it identifies the volume that maximises return, and where you break even.
Segments and labels
It can split the list into segments (e.g. high-potential vs standard), reserve a slice for testing under-explored supporters, and hold out a control group to measure impact.
Produces the final list
The output is a ranked, labelled contact list ready to export.
The profit curve, in plain terms
Imagine ordering every supporter best-first. As you add more, total income keeps rising but each extra contact adds cost and brings a less-likely supporter. Plot profit against volume and you get a hump: profit climbs, peaks, then falls.Optimal volume
The peak — contact this many for maximum profit.
Break-even
The point past which extra contacts cost more than they bring in.
Confidence band
A range around the peak — the curve is often flat on top, so nearby volumes are about as good.
Testing and fairness
Good programmes keep learning. A decision can:- Hold out a control group so you can prove the uplift versus not contacting.
- Reserve an exploration quota — deliberately include some lower-scored or under-contacted supporters so the model keeps learning about them rather than only ever mailing the obvious choices.
- Run experiments — split supporters into arms (e.g. standard vs higher ask) to measure what works.