MK-083 | Product progression from first to repeat purchase
For a regular chat, upload packs/mk-083.md. It includes the shared rules, this method, and required references
Purpose
This skill delivers: The product path after the first purchase
Products occurring in the same transaction do not establish psychological motives; a product pairing does not automatically prove cross-selling effectiveness
Required inputs
Available raw records: first-purchase SKU, quantity, purpose and use, available products and costs, later orders, and product cycles
Method Steps
- Use first SKU, quantity, purpose, usage conditions, and later orders to find the next unmet need. For directional advice, propose conditional paths from existing products without requiring complete second/third-purchase metrics
- Choose replenishment for a consumable approaching an evidenced usage cycle. Choose cross-product continuation when a compatible accessory or next-stage need exists while the main product remains usable. Do not force an unrelated, already-owned, or incompatible margin product
- For both second and third purchases, ask what the previous order resolved and what remains needed. Exclude already purchased or unsuitable products, then inspect stock, contribution, and contact eligibility
- Time replenishment from actual quantity/use or product-specific intervals; time complementary products from the usage stage. Without cycle data, give a trigger and request product-use evidence rather than imposing 10–14 days
- Replace the next product or date after a new order, remaining stock, changed use, or return. If the planned second product has been bought, move only to the next evidenced need
Calculation and Interpretation
When measurement is requested, next-product purchase rate = people in the same first-purchase cohort buying that product within the same horizon / the complete original first-buyer group, including nonrepeat buyers. Report product mix among repeat buyers separately. Deliver product, fit evidence, trigger, exclusions, and revision record for each step
Check example (hypothetical): a printer buyer explicitly needs duplex binding and a compatible binding accessory exists, supporting a next-step candidate. A new order shows that accessory was bought; remove the promotion and schedule consumable replenishment only when actual usage supports it
Decision rules authored by ThinkWithBlack, 2026-10-14; original course sources remain below
Required output fields
| Order | Field | How to complete |
|---|---|---|
| 1 | Source item | Use source evidence, an intermediate method result, or an explicit unknown; do not invent information |
| 2 | Target item | Use source evidence, an intermediate method result, or an explicit unknown; do not invent information |
| 3 | Supporting task | Use source evidence, an intermediate method result, or an explicit unknown; do not invent information |
| 4 | Evidence of fit | Use source evidence, an intermediate method result, or an explicit unknown; do not invent information |
| 5 | Applicable conditions | Use source evidence, an intermediate method result, or an explicit unknown; do not invent information |
| 6 | Unmatched items/conflicts | Use source evidence, an intermediate method result, or an explicit unknown; do not invent information |
| 7 | Next step | Use source evidence, an intermediate method result, or an explicit unknown; do not invent information |
Activation conditions and full question scope
Use this skill directly when the user wants follow-on purchase directions for existing customers or a progression from the first purchase to other brand products, including second and third purchases. The original method's ongoing purchases are not limited to the second order. Propose paths using the store's products, needs, and purchase data; a separate method named "third purchase" is not required
Real question Q005: "Sales have stalled, few customers buy a second or third time, and I don't want to keep increasing advertising investment. What direction could I take?" Original question. Preserve the constraint against continually increasing ads. A product progression is one applicable operating direction; the author's belief that ads are already optimized remains a self-report
Check SKUs, product costs, customer groups, purchase records, and product lines first. If unavailable, use the seven required fields to deliver conditional candidates, evidence of fit, and missing inputs; do not invent products, gross margins, cycles, or sales outcomes. Unless precise measurement is requested, do not make full-history segmentation or second-/third-purchase-rate calculations mandatory prerequisites
If the task is only to arrange a second product and reminder timing for someone who has bought once, use the first-buyer second-purchase planning method. If the request also includes cause diagnosis, actual repeat-purchase metrics, causal effects, loyalty programs, or platform configuration, retain every task and find the applicable methods; product progression cannot substitute for them. General operating advice is not a request to prove revenue has already increased; this skill does not promise an outcome
Verification cases
MK-083-C05 | One item has two distinct uses
Expected: List the uses and conditions separately; do not force a single match
Method sources
Source file: 營業額提升主要關鍵（一）縱深橫寬產品/產品線企劃策略
Location: Product
Source basis: extracted from course materials
Source URL: https://docs.google.com/presentation/d/1lIddPByRFVZeT-TR3CSaL_lEKkpJRloL6JQBLg1fO50/edit
English translation of source excerpt:
Product/product-line planning for depth and breadth
