Folks, please, don’t make the mistake that one head of marketing at Sierra I used to know did (and fought me tooth and nail on it, insisting that they were correct), and call the people you’re relying on to buy your product early in the game early adapters.
The phrase you are looking for is early adopter. Note the ‘O’. This is someone who is part of the first vanguard of people to ever use a new thing. They adopt the thing early on. (Adopt meaning “to take up and practice as one’s own”).
An early adapter, however, is someone who takes something early on, and like McGuyver or the A-Team, adapts it to their own nefarious purposes. This usually involves and/or incorporates duct tape somewhere in the process, a pocket-knife, and potentially a Sharpie permanent marker.
Similarly, one I saw today was regarding people doing things on mass. People, it’s French. en masse – as in, in a large group. At least with this one, there’s always the excuse that it’s written in a completely different language.