Where they are · The places · Element
The concentration
How much of the segment is in each place.
The part
What it is
A place holding a fifth of a segment is worth more than five places holding a twentieth each, because reach compounds within a place.
Concentration is what makes small specialist channels outperform large general ones for narrow audiences.
The smallest level
The attributes it carries
Each attribute is one of the framework’s shared types. What a date is, and how it is written, is defined once for the whole model — the note here says what it means in this particular place.