Interviewer view · keep this screen to yourself

Is an ad-supported plan worth as much as an ad-free one?

You run the case. Read the prompt, answer questions from the notes below, and share data only when the candidate asks for it or gets stuck. Score at the end.

Case timer

00:00

Target length:

1. Read the prompt aloud

Read it slowly, then pause. Let the candidate ask questions before they structure.

An illustrative streamer in the US sells an ad-free plan at USD 17.99 a month and a plan with ads at USD 7.99. A viewer on the ad plan watches 30 hours a month and sees 8 ads of 30 seconds per hour. The streamer sells all ad slots at a CPM of USD 20. What is the monthly revenue per ad-plan viewer?

2. Answers to clarifying questions

This case has no scripted clarifying answers. Answer from the prompt, and say "assume what you think is reasonable" if the prompt does not cover it.

3. A model structure

Compare the candidate's structure with this one. A different split can be just as good if it is clean and fits the problem.

Ad plan ARPU = subscription price + ad revenue per viewer
- Impressions = hours x ads per hour
- Ad revenue = impressions / 1,000 x CPM

4. The working, step by step

Each step shows how a strong candidate works it out. Share a new fact from it only when the candidate asks or is stuck, and let them do the math: the result in the dark box is what they should reach.

Step 1: Impressions per month
What a strong candidate does: 30 hours x 8 ads.
Ad impressions per viewer per month: 30 × 8 = 240
Step 2: Ad revenue per viewer
What a strong candidate does: 240 / 1,000 x USD 20.
Ad revenue per viewer (USD): 240 ÷ 1,000 × 20 = 4.8
Step 3: Total ARPU on the ad plan
What a strong candidate does: Subscription plus ads.
Ad plan ARPU (USD): 7.99 + 4.8 = 12.79

The recommendation to listen for

At the end, say: "The CEO walks in. What is your recommendation?"

The streamer should keep the ad plan, because it earns about USD 12.79 a month per viewer and attracts price-sensitive viewers who might not pay USD 17.99 at all. First, each viewer sees 240 ads a month, worth USD 4.80 at a USD 20 CPM, on top of the USD 7.99 fee. Second, this means each viewer who moves down from ad-free costs about USD 5.20 a month. The risk is that not all ad slots are sold, which cuts the USD 4.80. As a next step, track how many ad-free subscribers move down and the share of slots sold.

Score the candidate

Score each criterion from 1 to 5. A 2 or a 4 sits between the descriptions.

This case has no exhibit. Score Exhibit reading on how the candidate used the data you gave them: did they pick out the number that matters and say what it means?

Structuring

1: No clear structure, or a memorized framework that does not fit the problem.
3: A sensible structure, but with some overlap, a gap, or no clear priority.
5: A structure built for this problem, with no overlap and no gaps, a stated hypothesis, and a clear first step.

Math

1: Frequent errors, no units, or needed heavy help to finish.
3: Right answers but slow or messy working, or one error caught late.
5: Accurate and clearly narrated, with units, a sense check, and what the number means.

Exhibit reading

1: Read the chart aloud without finding the number that matters.
3: Found the key number but gave only part of the so-what.
5: Pulled the right number quickly and said what it means for the case.

Synthesis

1: Summarized what was done, with no clear answer.
3: Gave an answer, but with weak reasons or no next step.
5: Answer first, then two or three reasons with numbers, the main risk, and next steps.

Communication

1: Hard to follow: long silences, no signposting.
3: Clear most of the time, with some rambling.
5: Calm and concise, signposted each step, and checked in with the interviewer.

Total

0 out of 25

Score all five criteria to see the band and the feedback template.