// nicheindex.co / methodology
Act on insights, not instinct.
16,610+ publications. 27 topics. 327 segments. Every signal originates from observable newsletter behavior, not surveys, panel estimates, or platform aggregates.
// why index niches?
The newsletter market has a long tail, and the long tail is where the opportunity is.
Most attention goes to the top 50 newsletters everyone already knows. But the newsletter economy is 16,610+ publications deep, spread across 327 segments. The majority of growth, unoccupied market positions, and sponsorship white space exists in niches most people never think to look at.
Creators who pick a niche based on instinct compete against everyone who had the same instinct. Creators who pick a niche based on data (actual subscriber density, competition levels, monetization rates, and growth trends) find positions where the audience exists but the competition doesn't.
// the nicheindex score
100 = category average. Everything else is relative.
The NicheIndex Score is a composite index that measures newsletter health relative to category peers. A score of 100 means a newsletter performs at its category average across all dimensions. A score of 150 means it outperforms its category by 50%.
The score is built from six observable dimensions: audience size, editorial quality, engagement signals, growth momentum, monetization indicators, and publishing consistency. No single dimension dominates. A newsletter with massive reach but declining engagement won't score the same as one with moderate reach and strong momentum.
150+
Leader
Top of category
115–149
Strong
Above average
85–114
Average
Category norm
< 85
Below Avg
Room to grow
Browse real NI Scores across 27 topics, free.
// how the data works
01
Census
Refreshed daily
What does the market look like right now?
Every publication classified by niche, segment, and platform. Inactive newsletters excluded. This is the foundation. Without an accurate map, everything else is guesswork.
02
Behavior
Refreshed daily
Is this newsletter active, and is it growing?
Publishing cadence, subscriber trajectory, growth momentum, and content depth. Historical snapshots let you see trends, not just a single moment in time.
03
Intelligence
Derived from 01 + 02
What does this mean for your decision?
Competition density, gap analysis, and peer benchmarks. The NicheIndex Score distills it into a single number: 100 is the category average, and every point above or below tells you something actionable.
// data principles
Observed, not estimated
Real newsletter output: no surveys, no panels
If a metric can't be grounded in observable publication behavior, it isn't included. We don't impute audiences or infer engagement from proxies.
Updated daily
Live index, not a static report
Subscriber counts, activity signals, and competitive density refresh on a continuous cycle. Every metric carries a timestamp.
Can't be bought
Rankings reflect signals, not payments
No sponsored placements, no boosted profiles, no editorial adjustments. The system is designed so that option doesn't exist.
Active market only
Dead newsletters aren't competitors
Inactive publications are excluded from counts and gap analysis. We'd rather show a smaller, accurate market than a larger, misleading one.
// signal architecture — three layers, one index
16,610+ publications
27 topics · 327 segments
Layer 03 — Intelligence
Momentum
Growing · Steady · New
NI Score
100 = category avg
Layer 02 — Behavior
Cadence
frequency + recency
Content Depth
long · medium · quick
Layer 01 — Census
Subscribers
verified · daily refresh
Pricing Model
free · paid · hybrid
Market Intelligence
competition density · gap analysis · benchmarks
The intelligence layer is used by creators, operators, and media teams evaluating newsletter markets. Every metric has a timestamp. The data updates on its own schedule whether you're watching or not.
Still deciding? Here's what you can't get anywhere else.
vs. ChatGPT
AI gives you names. NicheIndex shows live subscriber counts, growth trends, and competition gaps across 327 segments. Real data, not hallucinations.
vs. scrolling Substack
You can find newsletters, but you can't see where demand exceeds supply, which segments are underserved, or who's growing vs. stalling.
vs. guessing
One good insight, the right niche, the right gap, pays for years of access.
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