Profit-Optimal Threshold Selection from an Interest Score
You have a per-user interest_score s ∈ [0, 1] for a new feature. The score distribution appears right-skewed. You can contact at most K users per week. Each contact has a known cost c. Let b(s) denote the expected incremental benefit (e.g., monetized uplift) if a user with score s is contacted.
Propose a principled method to choose a score threshold (e.g., 75th or 90th percentile) that maximizes incremental value under the cost constraint. Specifically:
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Define notation and the profit objective.
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Explain how to estimate b(s) from historical data, e.g., via isotonic calibration or splines.
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Show how to compute the profit-optimal cutoff using expected lift × margin − c, under a capacity constraint K.
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Explain how the approach adapts if the score distribution is left-skewed.
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Describe how to prevent instability due to sampling noise (e.g., Bayesian shrinkage or percentile CIs).
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Describe how to set up an ongoing backtest to validate the threshold against alternatives.
Provide formulas and a step-by-step selection algorithm.