How do you know if your ebook idea will sell?

Check 1: strangers are already searching

Type your topic into Etsy, Amazon, and Google and look for autocomplete suggestions and existing products. Strangers searching in their own words is demand you did not manufacture — the strongest signal available.

What you want to find: specific phrasing (“meal prep for night shift nurses”) with real products attached. What should worry you: total silence, or only giant broad books with nothing in your specific corner.

Check 2: they have paid for adjacent things

Look for money already changing hands near your topic: competing ebooks with reviews, courses with students, templates with sales, coaches selling the outcome. Reviews are especially valuable — three-star reviews on competing products are feature requests for yours.

Read those mid-tier reviews carefully and note every “I wish it covered…” That's your table of contents, dictated by buyers.

Check 3: people ask about it unprompted

Search Reddit, Facebook groups, and niche forums for questions matching your topic. Unprompted questions — asked to peers, not to you — prove the problem is alive enough that strangers spend social capital on it.

Collect ten real questions in the askers' own words. If you cannot find ten, the topic is either too narrow or too early. Both are survivable, but only with eyes open.

Check 4: a landing page pulls emails

Write the title, the one-sentence promise, and three chapter teasers on a single page, and ask for emails to hear when it launches. Fifty signups from relevant traffic is a pass; crickets from the right crowd is a fail worth believing.

Every EarnDraft book ships with a live marketing page you can use exactly this way — validate with the real page before you finish the real book.

• Pass: signups from people who match your reader sentence.
• Weak: traffic but no signups — fix the promise, not the book.
• Fail: no traffic at all — fix distribution before writing.