Three marketing concepts people mix up in interviews

Interviews for marketing roles often include a moment where someone asks a simple-sounding question: “What’s the difference between reach and frequency?” or “How would you balance brand and performance?” The question is rarely a trick. They’re listening for whether you understand the idea or have memorised the words.

Here are three pairs that trip people up most often, each explained with a picture you can keep in your head.

1. Reach vs. frequency

▸ Definition — Reach: how many different people saw your ad at least once. Frequency: how many times, on average, each of those people saw it.

Imagine you’re putting up posters for a concert. Reach is how many different people walk past at least one poster. Frequency is how many posters each of those people passes on an average day.

The two pull against each other on a fixed budget. You can show the ad once to lots of people, or several times to fewer people.

• High reach, low frequency suits a simple message people need to hear once: “Sale starts Friday.”
• Lower reach, higher frequency suits something that needs remembering or understanding: a new brand, a complicated product.

Impressions = reach × frequency

One million impressions could be 1 million people once, or 200,000 people five times. They are very different campaigns.

What interviewers want to hear: that you’d choose the balance based on the objective, and that you’d watch for frequency getting so high that people start ignoring or resenting the ad.

2. ROAS vs. ROI

▸ Definition — ROAS: revenue ÷ ad spend. ROI: (profit − cost) ÷ cost.

The simplest way to remember it: ROAS is about revenue; ROI is about profit. ROAS asks “how much money came in for each ad dollar?”. ROI asks “after paying for everything, did we end up with more than we started with?”

▸ Example — Spend $1,000 on ads, earn $3,000 in revenue: ROAS is 3.0. If the products cost $2,200 to make and deliver, profit is $3,000 − $2,200 − $1,000 = −$200, so ROI is −20%. Good-looking ROAS, money lost. Illustrative.

What interviewers want to hear: that you’d use ROAS to manage campaigns day to day, but set its target from the product’s margin and judge success on profit.

3. Brand vs. performance

▸ Definition — Brand marketing: building memory and preference over time, so people think of you and choose you when they’re ready to buy. Performance marketing: prompting and capturing a response now, measured directly (a click, a lead, a sale).

Think of a farmer. Brand marketing is planting and watering: nothing to harvest this week, but it decides how big next season’s crop will be. Performance marketing is harvesting: you see results straight away, but you can only harvest what’s already grown.

A common mistake is treating them as rivals. In practice:

• Performance channels capture demand that brand activity helped create.
• Brand activity makes performance cheaper, because people recognise and trust you when they see your search ad or product listing.
• Cutting all brand spend often looks fine for a quarter or two, then performance gets steadily more expensive.

What interviewers want to hear: that you see them as two jobs that support each other, measured differently. Brand is judged on things like awareness, consideration and long-term sales. Performance is judged on cost per result and profit.

▸ Margin note — You’ll sometimes hear specific budget splits quoted as the “right” balance between brand and performance. These come from particular studies and categories. Treat them as a starting point for discussion, not a rule.

A quick self-test

Take it to work

Next time someone asks you one of these, take a breath and use the picture: posters, revenue and profit, planting and harvesting. Clear beats clever.