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Case study · ecommerce · retention

The wrong default: When subscribe-and-save ships too often

An interactive case study: a pet food shop's subscribe-and-save defaults to every two weeks, but most bags last a month. The team tests a default that matches real use.

WXM 1 · Wonder (Look)WXM 2 · Architect (Plan)WXM 3 · Validate (Test)WXM 4 · Expand (Grow)
Teaching example
By Phil the CRO Guy

Phil the CRO Guy

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Updated

Slide 1 of 11

Kibble & Co: lots of subscribers, lots of cancellations

Kibble & Co sells dog food with a subscribe-and-save option. The delivery frequency defaults to every 2 weeks. Subscriptions start well, but many are cancelled within three months.

Phil looks at what the default is doing.

Defaults are powerful because most people keep them. That's great when the default is right, and expensive when it's wrong.

Slide 2 of 11

WXM 1 · Wonder (Look)

Wonder: what subscribers actually do

The team joins subscription data with order history.

  1. Most subscribers keep the 2-week default at sign-up.
  2. Within two months, many skip deliveries or change to 4 weeks.
  3. Those who didn't adjust are the most likely to cancel by month three.
  4. For the most popular bag size and typical dog weights, a bag lasts about 4 weeks.
Subscriber behaviour in the first 90 days (illustrative) Original wireframe, not a screenshot.
  1. Default mismatch. Most keep a frequency that's faster than they use the food.

Slide 3 of 11

WXM 1 · Wonder (Look)

Wonder: why do they cancel?

The cancellation survey and support tickets tell the same story.

  1. "I have three bags in the garage."
  2. "Too much food, too often."
  3. "I didn't realise I could change how often it comes."

Nobody cancelled because they disliked the food. They cancelled because the default didn't fit their dog.

Slide 4 of 11

WXM 1 · Wonder (Look)

Wonder: the subscription option today

Every subscriber starts at every 2 weeks, in a small dropdown most never touch.

Control (A)
Product page, subscribe-and-save, current version Original wireframe, not a screenshot.
  1. One size fits nobody. Every customer gets a 2-week default, whatever their dog and bag size.

Slide 5 of 11

WXM 2 · Architect (Plan)

Architect: from evidence to a hypothesis

Because most subscribers keep the 2-week default and later skip or cancel with 'too much food' as the main reason, we believe setting the default from bag size and the dog's weight (with a clear 'lasts about 4 weeks' estimate) will increase 90-day subscription retention without lowering subscription starts, because customers get food at the pace they use it.

Your turn: Which metric decides this test?
Show Phil’s answer

Active subscriptions and revenue per subscriber at 90 days. A slower default might lower short-term revenue per order. The goal is subscribers who stay. That only shows up weeks later.

Slide 6 of 11

WXM 2 · Architect (Plan)

Architect: a default that serves the customer

Defaults are a classic place for dark patterns: pre-selected subscriptions, frequencies chosen to maximise shipments, hard-to-find settings. [Source](#src-deceptive-design-types)

  1. One-time purchase stays equally visible.
  2. The frequency estimate is explained: "About 4 weeks for a 20 kg dog".
  3. Changing frequency or skipping is one tap, in every reminder email.

Slide 7 of 11

WXM 2 · Architect (Plan)

Architect: how does it score on PXL?

Noticeable at the decision point and backed by order data and cancellation reasons, but it changes a setting rather than adding or removing an element, and it needs a small calculator.

PXL score: 9 / 14

Is the change above the fold?Yes1
Is it noticeable within 5 seconds?Yes2
Does it add or remove an element?No0
Is it designed to increase user motivation?Yes1
Does it run on high-traffic page(s)?Yes1
Does it address an issue found in user testing?No0
Does it address an issue found in qualitative feedback (surveys, polls, interviews)?Yes1
Does it address insights found in digital analytics?Yes1
Is it supported by mouse-tracking heatmaps or eye tracking?No0
Ease of implementationUp to 8 hours2

PXL by CXL. A high score ranks an idea; it does not predict a win.

Slide 8 of 11

WXM 3 · Validate (Test)

Validate: the variation

A short question sets the default: the dog's weight. The frequency then defaults to how long the bag lasts, with the estimate shown.

Control (A)
A: fixed 2-week default Original wireframe, not a screenshot.
Variation (B)
B: default matched to the dog Original wireframe, not a screenshot.
  1. Right-sized default. The default fits the customer's real use, and says why.

Slide 9 of 11

WXM 3 · Validate (Test)

Validate: the test plan, written before launch

Fixed in advance:

  1. Early metric: subscription starts per visitor (should not drop).
  2. Decision metric: active subscriptions and revenue per subscriber at 90 days.
  3. Guardrails: skips, support contacts, one-time purchase rate.
  4. Timing: enrol for 4 weeks, then follow each cohort for 90 days before deciding.
  5. Decision rule: ship if 90-day retention improves and revenue per subscriber holds.

This test needs patience. Calling it on week four would reward the wrong default.

Slide 10 of 11

WXM 4 · Expand (Grow)

Expand: whatever the result, the cycle continues

This is a teaching case, so there's no result to report. Here's what each outcome would lead to.

  1. Win: apply matched defaults to other products (cat food, treats) and to reminder emails ('Running low?').
  2. Inconclusive: retention may depend more on reminders and easy skipping. Test those next.
  3. Loss: check whether the extra question lowered starts. Try a default based on bag size alone.

Slide 11 of 11

Your turn

List every default on your sign-up or checkout: plans, frequencies, add-ons, opt-ins. For each, ask: would most customers choose this if asked? Read the default effect before changing any.

What this case teaches

  • Wonder followed customers past the first order to find the cost of a bad default.
  • Architect used the default effect to help customers and built in easy ways to change.
  • Validate separated an early metric from the 90-day decision metric.
  • Expand linked the result to reminders and skipping.

Kibble & Co is a made-up shop used for teaching.

Frequently asked questions

What delivery frequency should subscribe-and-save default to?

The one that matches how fast most customers actually use the product. A default that's too frequent leads to stockpiles, skipped orders and cancellations; one that's too slow leads to customers running out and buying elsewhere.

Is Kibble & Co a real company?

No. It's a made-up shop used to teach the method, so there's no real result to report.

Sources (4)

  1. When and why defaults influence decisions: a meta-analysis of default effects. Jachimowicz, Duncan, Weber and Johnson, Behavioural Public Policy 3(2), 2019. Accessed 14 November 2026.
  2. Types of deceptive pattern. Deceptive.design (Harry Brignull). Accessed 4 November 2026.
  3. WXM: the Wave Experimentation Model. Wavesy. Accessed 4 November 2026.
  4. PXL: A Better Way to Prioritize Your A/B Tests. CXL. Accessed 4 November 2026.

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