Determine Optimal Budget Allocation for Maximum Profit
Quick Overview
This interview question evaluates metric design, causal reasoning, experiment setup, diagnostics, SQL/statistical checks, and recommendations in a realistic interview setting. A strong answer for Determine Optimal Budget Allocation for Maximum Profit states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Determine Optimal Budget Allocation for Maximum Profit
Company: Capital One
Role: Data Scientist
Category: Analytics & Experimentation
Difficulty: medium
Interview Round: Technical Screen
##### Scenario
You are given performance metrics for three acquisition platforms—live phone calls, social-media ads, and email campaigns—and a fixed marketing budget.
##### Question
With total budget B, cost-per-acquisition (CPA) and revenue-per-acquisition (RPA) for each platform, compute the expected net profit for every platform. 2. Using click-through and conversion rates, estimate the average cost incurred and profit earned from a single inbound phone call. 3. Each platform has a maximum spend cap. Given the same budget B, determine the optimal budget allocation across platforms to maximize overall profit.
##### Hints
Units purchased = budget/CPA; profit = units × (RPA − CPA). For allocation, rank by unit profit, fund highest until its cap, then move to the next.
Quick Answer: This interview question evaluates metric design, causal reasoning, experiment setup, diagnostics, SQL/statistical checks, and recommendations in a realistic interview setting. A strong answer for Determine Optimal Budget Allocation for Maximum Profit states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Determine Optimal Budget Allocation for Maximum Profit
Scenario
You have three user-acquisition platforms: Live Phone Calls, Social Media Ads, and Email Campaigns. You are given a total marketing budget B. For each platform i, you know its cost per acquisition (CPA_i) and revenue per acquisition (RPA_i). Each platform also has a maximum spend cap Cap_i.
Additionally, you have funnel metrics for the Live Phone Calls channel: click-through rate (CTR), click-to-call rate (q_call|click), and call-to-purchase (acquisition) rate (q_acq|call). Media buying cost may be given as cost per click (CPC) or cost per thousand impressions (CPM).
Assumptions (explicit):
CPAs and RPAs are average marginal values and remain constant within the relevant spend ranges (no diminishing returns within caps).
Budget is divisible (fractional expected acquisitions are acceptable).
For the phone-call funnel, if CPC is not given but CPM is, use CTR to derive CPC.
Questions
If you allocate the entire budget B to a single platform i, compute its expected net profit.
Using click-through and conversion rates for the Live Phone Calls funnel, estimate the average marketing cost incurred and expected profit earned from a single inbound phone call.
Each platform has a maximum spend cap. Given the same budget B and caps Cap_i, determine the optimal allocation across platforms to maximize total profit.
Hints
Units acquired = budget / CPA.
Profit = units × (RPA − CPA).
For allocation with caps, rank platforms by profit per dollar of spend and fund greedily until caps or budget are exhausted.
Clarifying Questions to Ask Guidance
Clarify the business objective, unit of analysis, time window, exposure definition, and primary metric.
State assumptions about instrumentation, randomization, sample size, and data quality.
Separate descriptive analysis from causal claims.
What a Strong Answer Covers Guidance
A metric framework with primary, guardrail, and diagnostic metrics.
A credible analysis or experiment design with clear assumptions and bias checks.
SQL/statistical logic for segmentation, variance, confidence, and data validation where relevant.
An actionable recommendation that explains trade-offs and next steps.
Follow-up Questions Guidance
What sanity checks would you run before trusting the result?
How would you handle novelty effects, seasonality, or selection bias?