R — Original Text (Reading)
When readers feel a product is a bit expensive, you can help them do the math by breaking the total price down into a per-day or per-use cost, so they discover "it's actually not that expensive." The key is that after averaging it out, you must compare it to a small, everyday expense the consumer is familiar with—"only 1.5 yuan a day, cheaper than a bottle of mineral water."
— Guan Jianming, Chapter 3, 3.2
I — Methodological Skeleton (Interpretation)
The core logic of the Math Persuasion Method: change the consumer's price perception by reframing the price.
Method 1: The Averaging Method (suitable for durable, high-priced goods)
- Determine the usage period: Estimate the product's reasonable service life (e.g., 5 years, 10 years, 365 uses).
- Calculate the average daily/per-use cost: Divide the total price by the number of days or times used.
- Compare with a familiar small expense: Find something the consumer spends money on daily with a similar amount for comparison (a bottle of water, a pack of tissues, a breakfast).
Method 2: The Savings Method (suitable for energy-saving/replacement products)
- Calculate the savings per use: Compare with the traditional option and calculate how much money is saved each time it is used.
- Multiply by usage frequency to get annual savings: Save X yuan each time x use Y times per year = save Z yuan per year.
- Show long-term savings: Amplify the annual savings to the total savings over the product's service life.
Key principle: The conclusion of the math must make the consumer feel that "this amount of money is nothing"—reinforce this feeling by comparing it to a familiar small expense.
A1 — Applications in the Book (Past Application)
Case 1: Dishwasher 2,800 yuan
- Problem: A dishwasher sells for 2,800 yuan, and consumers feel that "spending 2,800 yuan on a dishwasher is too extravagant."
- Use of the method: The averaging method—2,800 yuan ÷ 5 years (reasonable service life) ÷ 365 days = about 1.5 yuan/day. Then compare with a familiar expense: "1.5 yuan a day, cheaper than a bottle of mineral water, yet it can save you 30 minutes of dishwashing time every day."
- Conclusion: From "spending 2,800 yuan at once" to "spending only 1.5 yuan a day," the price perception undergoes a qualitative change.
- Result: Consumers shift from "too expensive" to "only 1.5 yuan a day, so worth it."
Case 2: Incremental cost of ecological rice
- Problem: Ecological rice is 5 yuan more per jin than ordinary rice, and consumers feel the premium is too high.
- Use of the method: Calculate the incremental cost—a family eats 20 jin of rice per month, and at 5 yuan more per jin, that is 100 yuan more per month. Then compare: "Spending 100 yuan more per month, less than the cost of one takeout meal, means the whole family can eat truly safe organic rice."
- Conclusion: Convert "5 yuan more per jin" (high relative premium) into "100 yuan more per month" (an acceptable absolute value), then compare it once with a takeout meal (a familiar expense), making the premium seem negligible.
- Result: The perception of the incremental cost is greatly reduced, and conversion increases.
Case 3: Water Purifier Water Savings
- Problem: Although the price of a water purifier is not high, consumers worry about subsequent usage costs (filter replacement, wastewater discharge).
- Application of the Methodology: The money-saving method — compared with traditional bottled water: bottled water costs 15 yuan per bottle, 4 bottles per month = 60 yuan/month = 720 yuan/year. Replacing the water purifier filter costs only 200 yuan per year, saving 520 yuan per year. Over 3 years, that saves 1,560 yuan, equivalent to the price of the water purifier itself.
- Conclusion: Through the money-saving method, the water purifier goes from "another expense" to "it pays for itself as you use it."
- Result: Consumers' focus shifts from purchase cost to usage savings, making the purchase decision easier to make.
A2 — Trigger Scenario (Future Trigger) ★
In what situations will users need this skill?
- The product has a relatively high unit price and consumers are hesitant, so the psychological threshold needs to be lowered.
- The product is more expensive than similar products, and consumers need to understand that "the extra money is actually very little."
- Energy-saving/environmentally friendly products need to demonstrate long-term economic benefits.
- Subscription/annual fee products need to make consumers feel that it is "only a few yuan a day."
- Incremental products (upgraded versions, higher-spec versions) need to make the price difference seem negligible.
Language Signals
- "Consumers think it's expensive, how do we make them feel it's not expensive?"
- "Help users do the math"
- "Only a few yuan a day"
- "More cost-effective in the long run"
- "How do we break the price down to each day?"
- "How do we show the product's money-saving effect?"
Distinction from Adjacent Skills
- Difference from
price-anchor: price-anchor creates a sense of a good deal by comparing with a higher-priced reference, while cost-accounting lowers perception by breaking down its own price. The former is "comparing with others," while the latter is "doing your own math." The two can be used in combination: anchor first, then do the math, to reduce price resistance on both fronts. - Difference from
customer-testimonial: customer-testimonial builds trust through user word of mouth, while cost-accounting lowers price perception through mathematical logic. The former solves the problem of "whether to believe it," while the latter solves the problem of "whether it's expensive."
E — Executable Steps (Execution)
- Determine which method to use
- Completion standard: Confirm the product type. Durable high-priced goods (home appliances, furniture, courses) → averaging method; energy-saving/replacement products (water purifiers, LED lights, energy-saving equipment) → money-saving method; incremental products (upgraded versions) → incremental averaging method.
- Averaging method — determine the usage period and daily average cost
- Completion standard: Write out the product's reasonable service life (years/months/days/times), and divide the total price by the total number of uses to get the daily or per-use cost. The number must be reasonable, and the usage period must not be exaggerated.
- Averaging method — find a comparison expense
- Completion standard: Find an item that consumers spend money on every day and whose amount is close to the daily average cost. Formula: "Only [X yuan] a day, equivalent to [a familiar small expense], even cheaper than [something]."
- Money-saving method — calculate the savings per use and the annual savings amount
- Completion criteria: Make a precise comparison with the traditional solution, calculate the amount saved per use, and multiply by the annual usage frequency to get the annual savings. The numbers must be based on real data.
- Money-saving method — show long-term savings
- Completion criteria: Show the total savings over the product's service life, preferably exceeding the price of the product itself ("the money saved is enough to buy another one").
- Final check
- Completion criteria: Confirm: (1) the service life estimate is reasonable and not exaggerated; (2) the comparison spending is a daily expense that the target consumer is truly familiar with; (3) the calculation logic is clear and consumers can understand it at a glance; (4) the conclusion can indeed make people feel that "this amount of money is nothing".
B — Boundary ★
Do not use this skill in the following situations
- Low-priced disposable consumer goods (such as snacks, tissues); doing the math instead makes people feel you are making a fuss over a trivial matter.
- Impulse purchases/emotional consumer goods (such as flowers, chocolate); rational calculation destroys the buying emotion.
- The product's service life is uncertain or very short (the calculated daily cost is not low, and instead exposes that it is "actually quite expensive").
- The target consumers are high-income groups (they are not sensitive to small price amounts, and doing the math seems beneath them).
Failure modes warned about by the author in the book
- Exaggerating the service life: In order to lower the daily cost, saying a product with a 5-year lifespan lasts 10 years; consumers are not foolish, and excessive exaggeration reduces trust.
- Unfamiliar comparison spending: "1.5 yuan per day, equivalent to half a steamed bun" — consumers have no spending perception of "half a steamed bun". You must choose an item that consumers spend money on every day.
- Complex calculation logic: If the calculation takes more than two steps, consumers cannot be bothered to look at it. "Total price ÷ number of days = daily average" in one step is best.
- The calculated number is still not low: If the amortized daily average is above 10 yuan, it will not look cheap compared with anything, indicating that the product pricing itself has indeed exceeded consumers' psychological threshold.
The author's blind spots / limitations of the era
- After 2017, consumers already have some immunity to the rhetoric of "only X yuan per day" (overused by industries such as insurance and courses), and more creativity is needed to avoid a "formulaic" feel.
- It does not discuss calculation strategies for membership/subscription scenarios — for example, "annual fee 299, equivalent to 24.9 per month" is already very common in SaaS and content platforms.
- It does not cover the calculation of "hidden consumption" — such as follow-up service fees for smart devices, filter consumable costs, etc. Consumers are increasingly concerned with the total cost of ownership rather than the one-time purchase price.
Related skills (to be filled in stage 3)
- depends-on: copywriting-four-step-system
- contrasts-with: price-anchor
- composes-with: price-anchor
Audit information
- Verification passed: V1 ✓ / V2 ✓ / V3 ✓
- Test pass rate: to be tested
- Distillation time: 2026-05-02