A sales letter is a landing page format rooted in direct-response marketing. Think long-form copy, personal tone (often from a named individual), storytelling that establishes the problem, a dramatic reveal of the solution, stacked proof, objection handling, and a strong close. It reads more like a letter than a typical landing page — because that's literally what it evolved from.
The format follows a reliable sequence: attention (hook) → problem agitation → solution → proof → offer → urgency → close. This structure, pioneered by direct mail copywriters like Gary Halbert and Eugene Schwartz, has been adapted for the web and still drives billions in online revenue. Course creators, info product sellers, and coaches use this format heavily because it works for considered, emotionally-driven purchases.
When to use a sales letter vs. a modern landing page
Sales letters perform best when the buyer needs to be sold — when they're not actively searching for your solution but can be persuaded through storytelling and proof. They're common for products where the value isn't immediately obvious: courses, consulting, methodologies, premium services. For SaaS products, e-commerce, or anything where the visitor already knows what they want, a modern landing page format typically outperforms.
The risk: bad sales letters feel manipulative. The line between persuasion and manipulation is honesty. If your proof is real, your claims are accurate, and the urgency is genuine, you're persuading. If you're fabricating testimonials, exaggerating results, or faking scarcity, that's manipulation — and it'll catch up with you through refunds and reputation damage.