Explain marketing mix modelling and how you would use it alongside attribution.

What the interviewer wants to hear

• MMM uses aggregated spend and outcomes over time with regression
• Captures offline, brand, seasonality and adstock or saturation effects
• Privacy-safe, no user tracking
• Needs long history and enough variation in spend
• Calibrate with lift experiments
• Use MMM for budget allocation, attribution for daily optimisation

Model answer

Marketing mix modelling is a statistical approach, usually regression, that links weekly or daily spend in each channel to sales, while controlling for factors like seasonality, price, promotions and the economy. It models adstock, the delayed effect of advertising, and saturation, where extra spend gives smaller returns. Because it uses aggregated data, it needs no cookies or user tracking and can include TV, outdoor and other offline media. It needs about two years of data and enough variation in spend to separate the channels' effects. Open-source tools like Google's Meridian and Meta's Robyn have made it more practical. I would calibrate the model with lift tests, since experiments give the most reliable causal results. Then I use MMM for quarterly and annual budget allocation, and platform or GA4 attribution for day-to-day optimisation within channels.

More hard Digital Marketing Specialist questions

• Leadership asks: if we turned off all paid social tomorrow, how many sales would we actually lose? How would you answer with evidence?
• The company asks you to cut the marketing budget by 30% but keep lead volume as close as possible to current levels. What do you do?
• Tell me about a campaign that failed. What happened, what did you learn and what did you change?
• Ad platforms now automate targeting, bidding and even creatives with AI. Where do you still add value, and what risks do you manage?
• The product head wants a big launch campaign for a new feature, while the sales head wants all budget on bottom-funnel leads this quarter. How do you handle it?
• The CEO wants to triple paid media spend next quarter. How do you decide whether and how to scale?
• Your company is launching its product in a new country, for example from India into the UAE. How would you plan the digital marketing?
• How would you build a first-party data strategy for a brand that currently relies on third-party targeting?
• Suddenly most of your marketing emails are going to spam. How do you diagnose and fix the problem?