Early Adopter
An early adopter is someone who buys or tries a new product well before it is proven, tolerating rough edges and missing features because the problem it solves is painful enough to be worth the risk.
What is an Early Adopter? Why They Are Not the Same as Your Whole Market
The term comes from Everett Rogers' diffusion of innovation curve, which splits any market into innovators (2.5%), early adopters (13.5%), early majority (34%), late majority (34%), and laggards (16%). Early adopters are not the very first people to try something, that's innovators, mostly tinkerers, but the first group willing to actually pay and rely on it.
Early adopters matter more than their small share suggests because they are self-selecting: they already feel the pain your product addresses acutely enough to seek out an unproven solution. They will forgive missing features and rough UI if the core problem is solved. That tolerance is a gift and a trap. A product that only ever appeals to early adopters, people who love trying new tools for their own sake, has not proven anything about the much larger early majority, who wait for references, case studies, and polish before switching.
Geoffrey Moore's Crossing the Chasm describes the gap between early adopters and the early majority as the point where most startups stall: they mistake enthusiasm from early adopters for product-market fit, then can't figure out why growth flattens once that pool is exhausted. If growth is decelerating even as reviews stay glowing, you may have saturated your early adopters and not yet built what the mainstream market needs.
Examples
Tesla's first Roadster buyers paid over $100,000 for a car from a company with no track record, because they wanted to be part of an electric car future badly enough to accept the risk. Tesla did not reach a mainstream buyer until the cheaper Model 3, years later.