Tumbletail Boxes: Profitability Case Study with Answer
Why did a fast-growing pet subscription box company swing from an $8.4 million profit to a $1.5 million loss, and how does it get back to profit? A free easy profitability case study with 4 questions, 2 exhibits and a model answer for every question. About 25 minutes. No login to read.
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Direct-to-consumer / Pet subscription boxes · Interviewer-led · McKinsey style
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The case
Our client, Tumbletail Boxes, ships a monthly box of dog or cat toys and treats to subscribers across the US. Boxes shipped grew from 2.4 million in 2023 to 3.0 million in 2025 and revenue rose from $72 million to $81 million, but operating profit went from $8.4 million to a loss of $1.5 million. The CEO wants to know why, and how to get back to profit next year.
Tumbletail started in 2019. Subscribers pay $32 a month and can cancel any time. Each box holds two toys and three bags of treats made by contract manufacturers, is packed in one warehouse in central Ohio and is shipped to the customer's door by a single national parcel carrier.
To grow faster, Tumbletail launched an intro offer in 2022: a new subscriber's first box costs $12 instead of $32. In 2024 the marketing team pushed the offer hard on social media and coupon websites. The head of growth credits the intro box for the extra volume, while the CFO blames a shipping rate increase for the loss.
Interviewer's data, shared if asked
- The list price has been $32 per box since 2021; there are no annual plans or other price tiers.
- The carrier raised its rates in January 2024, taking Tumbletail's shipping cost from $5.00 to $7.00 per box. A second national carrier has quoted $6.00 per box for the same box size and delivery speed.
- Box contents have not changed, so product cost has stayed at $11.00 per box.
- Two larger competitors charge $30 to $38 a month for similar boxes.
Question 1 · Structure
How would you structure your analysis of why Tumbletail lost money in 2025 even though it shipped more boxes?
Hint: Volume went up and profit went down, so the answer sits in profit per box or in fixed costs. Build the tree around one box.
Model answer
Profit = boxes shipped x contribution per box, minus fixed costs. Boxes went up 25%, so either each box now earns much less, or fixed costs jumped, or both. I would build the analysis around the economics of a single box.
Contribution per box is the price actually paid minus the variable costs of that box. The price paid depends on the mix of full-price boxes and discounted intro boxes, so I would split revenue by box type before blaming costs.
- Revenue per box: list price ($32) and the share of boxes sold at the $12 intro price.
- Variable cost per box: product (toys and treats), packaging and fulfillment, shipping.
- Fixed costs: marketing and overhead.
- Hypotheses to test: the intro offer is diluting revenue per box (head of growth's lever may be the problem); the carrier rate increase raised cost per box (CFO).
What the interviewer is looking for
- Good: a per-box profit tree with revenue and cost branches specific to a subscription box, not a generic list.
- Strong: splits revenue per box into full-price and intro boxes, so the discount can be tested, not just the costs.
- Excellent: turns the head of growth's and the CFO's views into two hypotheses and says which numbers would confirm each.
Push-back: The CFO is sure it is shipping. Why not just look at shipping and move on?
Question 2 · Math
Using Exhibit A, how did profit per box change between 2023 and 2025, and what explains the $9.9 million swing in operating profit?
| Line | 2023 | 2025 |
|---|---|---|
| Boxes shipped (millions) | 2.4 | 3.0 |
| Revenue ($M) | 72.0 | 81.0 |
| Product cost: toys and treats ($M) | 26.4 | 33.0 |
| Packaging and fulfillment ($M) | 9.6 | 12.0 |
| Shipping ($M) | 12.0 | 21.0 |
| Marketing ($M) | 9.6 | 10.5 |
| Overhead ($M) | 6.0 | 6.0 |
| Operating profit ($M) | 8.4 | -1.5 |
$ millions except boxes shipped.
Interviewer's data, shared if asked
- Intro boxes were 10% of boxes shipped in 2023 and 25% in 2025.
- The full-price box cost $32 and the intro box $12 in both years.
Hint: Divide each variable line by boxes shipped to get per-box economics for both years, then size each change at 2025 volume.
Model answer
Contribution per box halved, from $10.00 to $5.00. Revenue per box fell $3.00 ($30.00 to $27.00) and shipping per box rose $2.00 ($5.00 to $7.00); product and packaging stayed flat at $11.00 and $4.00 per box.
Revenue per box fell because of mix, not list price: intro boxes went from 10% to 25% of volume, and 0.9 x $32 + 0.1 x $12 = $30 while 0.75 x $32 + 0.25 x $12 = $27.
Bridging the $9.9 million drop: the lower revenue per box cost about $9.0 million on 3.0 million boxes, higher shipping about $6.0 million, and higher marketing $0.9 million. The extra 0.6 million boxes added back only about $6.0 million at 2023 contribution. Operating margin went from about 11.7% to about -1.9%.
| Per box ($) | 2023 | 2025 | Change |
|---|---|---|---|
| Revenue | 30.00 | 27.00 | -3.00 |
| Product cost | 11.00 | 11.00 | 0.00 |
| Packaging and fulfillment | 4.00 | 4.00 | 0.00 |
| Shipping | 5.00 | 7.00 | +2.00 |
| Contribution | 10.00 | 5.00 | -5.00 |
What the interviewer is looking for
- Good: computes per-box revenue and costs for both years and finds contribution fell from $10 to $5.
- Strong: names the two drivers, the $3 drop in revenue per box and the $2 rise in shipping, and sizes them in dollars.
- Excellent: explains the revenue drop as intro-box mix rather than a price cut, and shows that 25% more volume could not offset half the profit per box.
Push-back: Revenue grew $9 million. How can you say revenue is the biggest reason profit fell?
Question 3 · Math
Marketing proposes raising the intro box from $12 to $22. They expect 40% fewer intro boxes as a result. Using Exhibit B, what does this do to Tumbletail's annual profit?
| Metric | Full-price box | Intro box |
|---|---|---|
| Boxes shipped (millions) | 2.25 | 0.75 |
| Price paid ($ per box) | 32.00 | 12.00 |
| Product cost ($ per box) | 11.00 | 11.00 |
| Packaging and fulfillment ($ per box) | 4.00 | 4.00 |
| Shipping ($ per box) | 7.00 | 7.00 |
The intro box is the first box a new subscriber receives.
Interviewer's data, shared if asked
- In 2025, 20% of intro subscribers keep paying after their first box, down from 45% in 2023, after the offer appeared on coupon websites.
- A subscriber who stays buys on average 5 full-price boxes over the following year.
- Assume the subscribers lost to the higher price are typical, so 20% of them would have stayed.
Hint: First work out what one intro box and one full-price box earn. Then compare the money saved on intro boxes with the future full-price boxes you lose.
Model answer
Each full-price box earns $10 ($32 - $11 - $4 - $7), while each $12 intro box loses $10 ($12 - $22 of cost). Today the 0.75 million intro boxes lose $7.5 million a year.
At $22, an intro box breaks even exactly. Volume falls 40% to 0.45 million intro boxes, which now earn $0, so Tumbletail stops losing $7.5 million on first boxes.
The cost is the subscribers who no longer sign up: 0.30 million fewer intro boxes, of whom 20% (0.06 million) would have stayed and bought 5 full-price boxes at $10 each, or $3.0 million of lost contribution.
Net, profit rises by about $4.5 million a year, enough to turn the $1.5 million loss into about a $3.0 million profit. The move keeps paying unless more than 50% of the lost sign-ups would have stayed, far above today's 20%.
What the interviewer is looking for
- Good: finds that the intro box loses $10 each and that raising the price removes the $7.5 million first-box loss.
- Strong: asks how many intro subscribers stay and nets the lost future full-price boxes against the saving, landing on about +$4.5 million.
- Excellent: computes the 50% break-even stay rate and notes that a higher intro price may also attract more committed subscribers, so the 20% could improve.
Push-back: The head of growth says this kills our growth engine. What would you tell her?
Question 4 · Synthesis
The CEO has two minutes before her board call. What is your recommendation?
Hint: Lead with the action, then the two drivers with their sizes, then the expected impact, risks and next steps.
Model answer
Tumbletail should reprice the intro box to $22 and rebid its shipping contract. Profit per box halved from $10 to $5 for two reasons: $12 intro boxes grew from 10% to 25% of volume, cutting revenue per box by $3 (about $9 million), and a carrier rate rise added $2 per box (about $6 million). The 25% volume growth won back only about $6 million.
A $22 intro box adds about $4.5 million a year even after counting lost future boxes, which turns the $1.5 million loss into about a $3.0 million profit. Moving to the second carrier's $6.00 quote is worth about $3 million more at 2025 volume.
The risk is slower growth. I would test the $22 offer in a few regions for eight weeks, pull the offer from coupon websites now, and track how many intro subscribers keep paying.
What the interviewer is looking for
- Good: opens with a clear action and names the intro discount and shipping as the two drivers.
- Strong: gives the size of each driver and of each fix, consistent with the earlier math.
- Excellent: proposes a regional test with a clear metric (intro subscriber stay rate) and says what result would change the call.
Model recommendation
Show the recommendation
Get Tumbletail back to profit by raising the intro box price from $12 to $22 and moving shipping to the carrier that quoted $6.00 per box.
Profit fell $9.9 million because contribution per box halved from $10 to $5: cheap intro boxes rose from 10% to 25% of volume (about $9 million) and shipping rose $2 per box (about $6 million). Shipping 25% more boxes added back only about $6 million.
A $22 intro box adds about $4.5 million a year even with 40% fewer sign-ups, turning the $1.5 million loss into about a $3.0 million profit; the cheaper carrier is worth about $3 million more at 2025 volume.
Next steps: test the $22 offer in a few regions for eight weeks, take the offer off coupon websites, and track the share of intro subscribers who keep paying.
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Written by Road to Offer. Updated November 6, 2026. Every client and number in this case is made up for practice.