Larkin Company Order Form (1914)
The pattern
This still is filed under Direct-mail response.
Define
A physical letter or pack whose only job is a measurable reply: an order, a donation, a call.
Mechanism
Response engineering. Outer, letter, lift, reply device. Every surface earns its keep or it is cut.
Verdict
We can mail, track, and fulfill, and the unit economics survive the stamp.
Why it works
It acts as an entire self-contained sales ecosystem, gamifying the ordering process by dedicating specific sections to claiming rewards and referring new customers.
Steal this when
Designing a physical or digital checkout flow that needs to capture referrals and apply loyalty rewards without a separate step.