Fortresses
Hard to copy, hard to dislodge, and they grow without growing costs. All three at once is rare.
14 teardownsEurope's clothes resale. Buyers pay, sellers don't.
Readers pay by the chapter. Tencent films the hits.
Japan runs on business cards. Sansan digitized them.
The bootstrapped stock-asset market that paid out $1.3B
Global marketplace for pre-owned luxury watches.
Sells software lifetime deals to a 1.5M-buyer list.
Fingerprints a site's tech stack — then sells the reverse.
Flat $69/mo to hire from 2M Filipino workers.
Real estate's town square — a free forum, 3M+ members.
under 1% pay
Find the best city to live & work as a nomad — by data.
niche + travel churn
The accessibility test engine Google & MS use.
The virtual tabletop you buy once, not rent.
Google indexes web pages. Shodan indexes devices.
Build your fictional world — a wiki for writers & GMs.
small TAM · free-heavy