Performance marketing math questions.

68 performance marketing math questions from the bank, ready to practice out loud.

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STAR and CARL: structuring your story Unit economics: ROAS, margin, and LTV Attribution models vs incrementality Budget allocation and the media mix CAC three ways: blended, paid, and marginal

All 68 questions

CAC spike investigationYour blended CAC just jumped from $40 to $65. LTV is $180. Walk me through what you investigate first.Unit economics mathMid–senior

Questioning last-touch attributionYour last-touch attribution says paid search is the hero. Walk me through why you might not believe it.Attribution model selectionMid–senior

Blended CAC versus paid CACWalk me through the difference between blended CAC and paid CAC, and when each matters more for decision-making.Blended vs paid CACMid–senior

LTV calculation for subscriptionWalk me through your LTV calculation for a consumer subscription with 5% monthly churn and $15 ARPU.LTV assumptionsMid–senior

Scaling decision at 100% ROASWalk me through how you'd diagnose whether you should scale up or pull back from a paid channel that's at 100% ROAS.Channel Level ROISenior–staff+

How doubling spend affects CACIf you doubled paid spend tomorrow on the same campaigns, would CAC stay the same? Walk me through.Unit economics mathMid–senior

Incrementality test for always-on channelWalk me through how you'd run an incrementality test for an always-on paid channel.Attribution model selectionSenior–staff+

Blended CAC improving divergenceYour blended CAC is improving but your paid CAC is getting worse. What's likely going on?Blended vs paid CACSenior–staff+

LTV horizon disagreement with CFOYour team is using a 24-month LTV. Your CFO says use 12. Walk me through how to bridge the conversation.LTV assumptionsSenior–leadership

CAC across sales cyclesWalk me through how you'd compare channels with very different sales-cycle lengths on a single CAC dashboard.Channel Level ROISenior–staff+

CAC payback period spending implicationsYour CAC payback period is 14 months. What does that tell you about how aggressively you can spend?Unit economics mathSenior–staff+

Data-driven vs. position-based attributionWalk me through when you'd choose data-driven attribution over a position-based model.Attribution model selectionSenior–staff+

Expanding paid CAC conversationYour CEO uses paid CAC as the single growth metric. Walk me through how you'd improve that conversation.Blended vs paid CACSenior–leadership

Handling high-LTV users skewing averagesWalk me through how you'd handle the case where a small set of high-LTV users is skewing your average.LTV assumptionsSenior–staff+

High ROAS with poor retentionWalk me through how you'd treat a channel that has great direct ROAS but poor downstream retention.Channel Level ROISenior–leadership

Discussing optimistic LTV with CFOYour team is spending against an LTV that's increasingly looking optimistic. Walk me through your conversation with the CFO.Unit economics mathSenior–leadership

MMM validation before relianceYour data team is moving to MMM for the first time. Walk me through what you'd want them to validate before relying on it.Attribution model selectionSenior–staff+

Reporting CAC with organic-paid overlapWalk me through how you'd report on CAC when your organic growth depends partly on paid spend driving awareness.Blended vs paid CACSenior–leadership

Assessing trustworthiness of LTV numbersWalk me through what makes you trust an LTV number more or less when you see it.LTV assumptionsSenior–leadership

Choosing between equal-CAC channelsTwo channels both deliver $20 CAC. Walk me through what would still make you pick one over the other.Channel Level ROIMid–senior

CAC drop versus LTV growthWalk me through whether you'd rather have your CAC drop 10% or your LTV grow 10%.Unit economics mathSenior–staff+

Reconciling MTA, MMM, and incrementalityWalk me through how you'd reconcile MTA, MMM, and incrementality tests if all three disagree.Attribution model selectionSenior–leadership

Computing CAC for freemium productsWalk me through how you'd think about CAC for a freemium product where most customers never pay.Blended vs paid CACSenior–leadership

Modeling LTV with improving marginsWalk me through how you'd model LTV for a product where margins are increasing over time.LTV assumptionsSenior–staff+

Allocating budget in no-growth quarterWalk me through how you'd allocate budget between brand and performance channels in a no-growth quarter.Channel Level ROISenior–leadership

Marginal versus average costWalk me through how you'd compute the marginal cost per acquisition versus the average cost.Unit economics mathSenior–staff+

Attributing word-of-mouth in CACWalk me through how you'd attribute organic word-of-mouth in a CAC dashboard.Attribution model selectionSenior–leadership

Paid and blended CAC divergingWalk me through what you do when paid CAC and blended CAC trend in opposite directions for three months in a row.Blended vs paid CACSenior–leadership

LTV with pricing changesWalk me through how you'd handle LTV math when subscription pricing has changed multiple times.LTV assumptionsSenior–staff+

Capping spend on highest-performing channelsWalk me through whether you'd cap spend on your highest-performing channel and why.Channel Level ROISenior–leadership

Facebook campaign ROASWalk me through how you'd calculate ROAS for a Facebook campaign that spent $5,000 and generated $12,000 in revenue.Channel Level ROIEntry–mid

Evaluating paid social channel profitabilityYour paid social channel has a $50 CAC and customers have an average order value of $80 with 40% gross margin. Walk me through whether this channel is profitable.Unit economics mathEntry–mid

First-touch versus last-touch attributionWalk me through what first-touch attribution means and when you'd use it versus last-touch.Attribution model selectionEntry–mid

Calculating blended CAC across channelsYou have 1,000 paid acquisitions at $30 each and 500 organic acquisitions in the same month. Walk me through how to calculate blended CAC.Blended vs paid CACEntry–mid

Estimating e-commerce customer LTVWalk me through how you'd estimate LTV for an e-commerce customer who makes an average of 3 purchases per year at $50 each, staying for 2 years on average.LTV assumptionsEntry–mid

Interpreting 3:1 ROAS performanceYour Google Ads campaign has a 3:1 ROAS. Walk me through what that means and whether it's good.Channel Level ROIEntry–mid

Channel CAC aggregation errorWalk me through why you can't just add up all your channel-specific CACs to get a company-wide CAC.Blended vs paid CACEntry–mid

LTV with limited dataYou're calculating LTV but only have 6 months of customer data. Walk me through what assumptions you'd need to make.LTV assumptionsEntry–mid

Linear attribution and customer journeysWalk me through how linear attribution works and what type of customer journey it works best for.Attribution model selectionEntry–mid

Paid vs blended CACYour paid search CAC is $40 but your blended CAC is $25. Walk me through what this tells you about your acquisition mix.Blended vs paid CACEntry–mid

Calculating contribution margin per customerWalk me through how you'd calculate the contribution margin per customer if your product sells for $100, has $35 COGS, and $50 CAC.Unit economics mathEntry–mid

TikTok vs. email CAC comparisonYour TikTok ads delivered 200 conversions at $2,000 spend while your email campaign delivered 150 conversions at $300 spend. Walk me through which has better CAC and CPA.Channel Level ROIEntry–mid

LTV calculation from retention cohortsYour retention cohorts show 80% month-1, 65% month-2, 55% month-3, then flat at 50%. Walk me through how you'd calculate LTV and what assumptions you're making.LTV assumptionsMid–senior

Meta vs Google ROASYou're running Meta and Google. Meta reports 3x ROAS, Google reports 4x. Walk me through how you'd decide which one to scale next week.Channel Level ROIMid–staff+

Valuing affiliate channel true contributionYour affiliate channel shows a $25 CAC but it's all last-touch attributed. Walk me through how you'd value this channel's true contribution.Attribution model selectionSenior–leadership

LTV modeling for freemium productsWalk me through how you'd build a cohorted LTV model for a freemium product where 3% of users convert to paid after 60 days on average.LTV assumptionsMid–senior

Spending strategy with organic growthYour paid CAC is $80, blended is $50, and organic is growing 15% month-over-month. Walk me through your spending strategy for next quarter.Blended vs paid CACSenior–leadership

Contribution margin with variable costsWalk me through how you'd calculate contribution margin per customer when gross margin is 60% and monthly variable costs per user are $4.Unit economics mathEntry–mid

First-touch vs. linear attribution gapYou're testing first-touch vs. linear attribution. First-touch gives paid social a $45 CAC, linear gives $72. Walk me through what this tells you about the customer journey.Attribution model selectionMid–senior

CAC affordability for SaaSYour SaaS product has 3% monthly churn and $50 ARPU. Your CFO asks if we can afford a $600 CAC. Walk me through your answer.Unit economics mathMid–senior

Budget allocation across three channelsWalk me through how you'd allocate a $500K monthly budget across three channels with CACs of $30, $55, and $90 if LTV is $200.Channel Level ROIMid–senior

Paid search cannibalizationYour paid search CAC is $40 but when you pause it for a week, organic drops 20%. Walk me through how this changes your view of the channel.Channel Level ROISenior–leadership

CAC payback vs break-evenWalk me through the difference between CAC payback period and break-even time, and when each metric matters more.Unit economics mathMid–senior

Blended vs. paid-only CAC trade-offYour blended CAC is $35 but when you model paid-only growth, CAC would be $90. Walk me through how you present this trade-off to leadership.Blended vs paid CACSenior–leadership

CAC with long sales cycleYou have a 90-day sales cycle. Walk me through how you'd measure CAC for conversions happening this month from spend three months ago.Unit economics mathMid–senior

Onboarding dropout and CAC targetsYour mobile app LTV is $45 but 40% of users never make it past onboarding. Walk me through how you'd adjust your CAC target.LTV assumptionsMid–senior

Holdout test for display incrementalityWalk me through how you'd set up a holdout test to measure the incrementality of your display advertising spend.Channel Level ROISenior–leadership

Referral LTV premiumYour data shows customers acquired via referral have 2x the LTV of paid customers. Walk me through how this changes your CAC targets by channel.LTV assumptionsSenior–leadership

LTV calculation for two-sided marketplacesWalk me through how you'd calculate LTV for a two-sided marketplace where you acquire both buyers and sellers.LTV assumptionsSenior–leadership

Attribution window vs. decision cycleYour attribution window is 7 days but your average purchase decision takes 21 days. Walk me through the implications for your CAC measurement.Attribution model selectionMid–senior

CAC efficiency across churn ratesWalk me through how you'd compare the efficiency of a $20 CAC channel with 10% churn vs. a $35 CAC channel with 5% churn.Unit economics mathMid–senior

iOS vs. Android channel allocationYour iOS CAC is $65, Android is $40, but iOS LTV is only 1.2x Android LTV. Walk me through your channel allocation strategy.Channel Level ROIMid–senior

Blended CAC with partnership feesWalk me through how you'd measure blended CAC when 30% of customers come through an unpaid partnership that required a $200K annual fee.Blended vs paid CACSenior–leadership

Retargeting cannibalization testingYour retargeting campaign shows a $15 CAC. Walk me through how you'd test whether it's stealing conversions from other channels.Attribution model selectionMid–senior

Discount rate in LTVWalk me through how discount rate assumptions in your LTV model affect how much you're willing to pay for a customer today.LTV assumptionsSenior–leadership

Brand campaign without last-touch creditYour brand campaign doesn't get last-touch credit but when you pause it, all channel CACs rise 25%. Walk me through how you'd value it.Channel Level ROISenior–leadership

Seasonal conversion volatilityWalk me through how you'd build a CAC model that accounts for seasonal conversion rate swings of 40% between Q4 and Q1.Unit economics mathMid–senior

Incrementality without attributionWalk me through how you'd measure incrementality for a multi-channel campaign when your attribution model is broken.Attribution model selectionSenior–leadership