Demand signals are the public mentions, praise and complaints readers post on BookTok, Reddit and Goodreads, which can show what they want before sales data does. This guide covers the four sources, how to weigh them against each other, how to do the reading yourself, and how Tropesmith automates it.
Listen before you pitch: book lovers say what they want on BookTok, Reddit and Goodreads, so write toward what they keep talking about, check the shelf, then reach them through a newsletter you own and swaps with other authors. A Tropesmith Map sets those signals against the books already on Amazon in your lane.
When a trope, aesthetic, or title catches on BookTok, the play counts are enormous and the effect on sales is real — entire subgenres have been lifted by it. The signal to read isn't just which books are going viral but which promises: the tropes and feelings named in captions and comments.
Reddit's romance communities are full of request threads: “I want a book where…”, “looking for something like X but with Y…”. This is demand in its purest form — a reader explicitly describing a book they cannot find. When the same ask recurs across threads, that is a premise worth checking against the shelf.
The shelves readers create are a folksonomy of how readers actually categorise books — the exact vocabulary they use, which is worth more to your blurb and keywords than any thesaurus. Reviews add the verdict layer: what readers of a book loved, and what they wished it had done. A recurring “I wish…” in a subgenre's reviews is a quieter, more considered cousin of a Reddit request thread.
Strictly, Amazon shows supply and its performance — but it's the indispensable cross-check. Demand without a supply check can send you chasing something the market already delivered, so check how many books already carry a signal before you act on it.
The sources disagree constantly, so read them side by side rather than trusting any one. Of Tropesmith's demand signals, 95.6% come from Goodreads and Amazon reviews, 4.1% from BookTok comments and captions and 0.3% from Reddit posts, so a premise that also shows up on BookTok and Reddit is worth a second look. Then cross-reference it against Amazon supply to see how many books already carry it. You can do the same by hand: a trope that's viral on BookTok, requested on Reddit, and thin on the bestseller shelf is worth checking first.
Counted 2026-10-07 17:24 UTC. A demand signal is one specific thing a reader asked for or praised in a review, comment or post, picked out by Tropesmith's classifier. One review can give several. Each signal gets a rarity tag (common, underserved or novel) from the text of that review or post alone; the classifier is never shown what is on the shelf. A tag points at where to look. It does not prove that no book answers the signal. Shares are the tagged signals divided by all signals in the same scope. How we count
Weigh repetition over volume. One viral video is an event; the same craving surfacing across BookTok comments, Reddit posts, and Goodreads reviews is a market.
Pick the BookTok hashtags for your subgenre and skim weekly. Read comments, not just videos — comments are where readers say what they want next.
Search romance book-recommendation communities for your lane's keywords, sorted by new. Save every ask that matches your territory; recurring phrasings are the finds.
Newest reviews of comparable titles (see finding comps) tell you where current readers are delighted and where they're still hungry.
Half an hour a week keeps you conversant; genuinely mapping demand for a lane — reading it across all sources, weighing it, checking supply — is a job measured in days. That's the layer Tropesmith industrialises: the engine reads BookTok virality, Goodreads shelves and reviews, and Reddit posts, and cross-references Amazon supply. You can see the output free on Trope check and Demand Signals. A Map turns that corpus into a verdict for your exact book — and the gaps it names come backed with the reader quotes that revealed them. Demand data is one input to the larger question of what to write; for the full decision, start at what romance subgenres sell.
Listen before you pitch: book lovers say what they want on BookTok, Reddit and Goodreads, so write toward what they keep talking about, check the shelf, then reach them through a newsletter you own and swaps with other authors. A Tropesmith Map sets those signals against the books already on Amazon in your lane.
Public evidence of what readers say they want or praise: BookTok comments and captions, requests in Reddit romance communities, and the shelves and reviews readers create on Goodreads and Amazon. Read together and checked against Amazon supply, they show what readers are talking about and how many books already carry it.
Goodreads reviews, Amazon reviews, BookTok comments and captions, Reddit posts and Amazon Q&A. 95.6% come from Goodreads and Amazon reviews, 4.1% from BookTok comments and captions and 0.3% from Reddit posts (source shares counted 7 October 2026).
Yes: follow your lane's BookTok hashtags, search romance recommendation threads weekly, and read fresh reviews of your comp titles. Tropesmith's free Trending, Demand Signals, and lane snapshot pages surface the engine's counts at no cost; the paid Map draws on the corpus for your specific lane.
A Tropesmith Map weighs BookTok, Reddit and Goodreads demand against Amazon supply for your exact lane — with the gap named.
Build my Map — $15 → See a real sample Map first →Data referenced on this page: Tropesmith market snapshots — refreshed as the market moves. Guides are part of the romance market intelligence hub.