Right idea, wrong platform decade — app-intent routing was impossible on iOS/Android in 2011 but shipped to every phone by 2024 as MCP and App Intents.
A Stanford senior raised a record-breaking $30M seed, then burned three years shipping no product before Apple Pay made the whole premise moot.
Hit the top of the App Store by routing anonymous posts through your real-name contact graph, then disintegrated under the weight of harassment its own design guaranteed.
A used-car C2C marketplace whose logistics and inspection costs exceeded GMV margin on every transaction — $149M burned to confirm the economics don't close.
Raised $945M on a claim the founder knew was not technically achievable; the revival signal here is negative — you can learn from Theranos precisely what not to rebuild.