You are launching a new gadget. The textbook says: win the "innovators and early adopters" first. So pick the two people you would target as most likely to adopt it first.
The two who adopted first are your "innovators", and notice: nobody adopted early because of a personality trait. Each did it for a circumstantial reason, a job that suddenly needed it, a friend who had one. The confident-looking "gadget geek" and "trend-follower" landed in the middle or late.
That is the catch with adopter categories (Rogers, 2003). "Innovator" and "early adopter" are defined purely by when someone adopts, so they are labels you can only pin on afterwards, not a segment you can spot before launch. The famous 2.5% and 13.5% are just slices of a bell curve of adoption timing, not a discovered personality type.
So use the S-curve and the Bass model to forecast how fast something will spread, but drop the "early adopter persona" as a targeting plan, it exists only in the rear-view mirror.