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Day 16 of 90

Price & Promo Reasoning

7 min read

Key Concepts

  • 1Agents must reason about effective price, not list price — stacking coupons, tier discounts, loyalty points, and shipping thresholds change what the user actually pays
  • 2Promotion logic is combinatorial and rule-heavy; the agent needs a reliable pricing engine to call, not an LLM guessing which discounts stack
  • 3Threshold nudges are high-value: 'add $8 to hit free shipping' is a genuine service that also lifts AOV — the agent should surface these proactively
  • 4Never let the LLM invent or approximate prices; pricing must be authoritative and real-time, because a wrong quoted price is a trust and potentially legal failure
  • 5Promo eligibility depends on context (first-time buyer, region, cart contents), so the agent must pass full cart state to the pricing service to get a correct answer
  • 6Transparency in savings framing builds trust: showing the real before/after and the reason for a discount beats vague 'special price' language
  • 7Time sensitivity: expiring promos and price changes mid-session must be re-validated at checkout so the quoted price and the charged price always match

Why It Matters for PMs

AOV lever: Proactive threshold and bundle nudges convert directly into larger baskets — one of the clearest revenue impacts an agent can have when pricing reasoning is correct.
Trust and legal integrity: A quoted price that differs from the charged price destroys trust and can violate consumer-protection law. Authoritative, real-time pricing is non-negotiable.
Margin control: Reasoning about stacked discounts prevents accidental over-discounting, protecting merchant margin while still delivering the savings the customer expects.

Test Your Understanding

Question 1 (Multiple Choice)

Why should an agent call a pricing engine rather than let the LLM compute discounts?

Question 2 (Multiple Choice)

A user's cart is $42 and free shipping is at $50. What is the highest-value agent behavior?

Question 3 (Multiple Choice)

Why must a quoted promo price be re-validated at checkout?

Question 4 (Short Answer)

How would you design the agent-to-pricing-engine boundary so the LLM never quotes an incorrect price?

Think about your answer before revealing the explanation.

Question 5 (Short Answer)

What's the tradeoff between aggressive promo nudging (higher AOV) and coming across as pushy?

Think about your answer before revealing the explanation.