NicheIndex | Newsletter Market Intelligence

# NicheIndex > NicheIndex is a newsletter market intelligence platform that indexes 16,870 newsletters across 27 categories and 318 niches. It covers Substack, Ghost, Beehiiv, and other platforms. It provides real subscriber data, growth signals, competitive positioning, and market gap analysis, updated daily from real data, not AI-generated estimates. - Data is sourced from public endpoints and RSS feeds, updated daily - Subscriber counts, growth trends, and behavioral signals are based on real snapshots - NicheIndex tracks momentum (Growing/Steady/Slowing), posting activity, and content depth - Free newsletter discovery is available at /discover - Paid intelligence includes niche breakdowns, competitive positioning, and growth trends ## Docs - [Browse Newsletters](https://nicheindex.co/discover): Free newsletter discovery across all indexed categories - [About NicheIndex](https://nicheindex.co/about): How and why NicheIndex was built - [Methodology](https://nicheindex.co/methodology): How newsletters are scored and ranked - [Pricing](https://nicheindex.co/pricing): Full market intelligence access ## Categories - [Best Art & Illustration Newsletters](https://nicheindex.co/discover/arts): 690 newsletters tracked - [Best Business Newsletters](https://nicheindex.co/discover/business): 790 newsletters tracked - [Best Climate & Environment Newsletters](https://nicheindex.co/discover/environment): 870 newsletters tracked - [Best Comics Newsletters](https://nicheindex.co/discover/comics): 413 newsletters tracked - [Best Crypto Newsletters](https://nicheindex.co/discover/crypto-web3): 490 newsletters tracked - [Best Culture Newsletters](https://nicheindex.co/discover/culture): 590 newsletters tracked - [Best Design Newsletters](https://nicheindex.co/discover/design): 757 newsletters tracked - [Best Education Newsletters](https://nicheindex.co/discover/education): 657 newsletters tracked - [Best Faith & Spirituality Newsletters](https://nicheindex.co/discover/faith-sp