Mail-Order Made Easy
The pattern
This still is filed under Mail-order catalog.
Define
A catalog that is the store: browse, choose, order, without a clerk and often without a website.
Mechanism
Assortment as argument. Density, numbering, and an order path do the closing. The book is the funnel.
Verdict
We have a range, remote buyers, and a way to take the order on the same object.
Why it works
The whole book is built as a chain of questions, and every chapter head is one, which forces the material into the order a beginner would actually meet it in. Rittenberg leads with the disqualifier rather than the promise: he states the two conditions under which mail-order can pay and tells the reader not to attempt it otherwise, which buys credibility for everything that follows. The teaching method is contrastive, showing the weak version of a headline then the corrected version, so the principle is inferred from a visible before and after rather than asserted. The elimination principle, that the advertisement should state or show at once what is being sold in order to select its readers out of the mass, is the same audience-filtering logic he later applies to media, guarantees and keying.
Steal this when
Steal the question-as-chapter-title structure when you are writing the definitive primer on a subject for people who do not yet know what to ask. Steal the opening disqualifier when your method genuinely fails for a large slice of the audience and you would rather lose them early than carry their failures as evidence against you.