Affinity is a measure of the likelihood that the target group (i.e. the people represented by each cell in Audience Map) will be in your audience compared to the general population of Facebook (in the United States).
An affinity score is calculated for each cell in an Audience Map. Each cell represents the intersection of a gender/age grouping and another demographic or interest (e.g. education level or music preference). There is a cell for men aged 25-34 who like jazz music, for example. The higher the affinity score the more likely it is to find someone fitting that description in your audience than in the general Facebook population (i.e higher affinity). The lower the score, the less likely (i.e. a lower affinity). The probability of finding the target group in your audience is compared with the probability of finding it in Facebook’s general population, and those probabilities are used to calculate an affinity score that represents the relative strength (or weakness) of that likelihood.
Shades of red represent greater likelihood (affinity). The darker the shade of red, the greater the affinity. Conversely, shades of blue represent lesser affinity. White means that the likelihood is the same as for Facebook’s general population. Gray diagonal hatching will appear in one of two situations:
- The size of the audience represented by that cell is below 1000 and therefore too small to yield a significant result, or
- Facebook has no data for that portion of the population.
The affinity key shown in the upper left corner of the map describes the color scale used. You also can hover above each cell with your cursor to obtain the exact affinity score for that cell. The color scale shows affinity scores from 0 to 6, because 95% of the data analyzed by Tapcast fall within this range. The shade of red is the same for affinity scores higher than 6. In such cases, a small plus (+) sign appears in the cell. You can hover over the cell if you wish to see the exact score.