Facebook has Graph Search, which allows finding people by specifying information about them. Facebook, LinkedIn, and Google ads services allow counting the number of people who search certain phrases or fit some characteristics.
Where can I find a kind of reverse of this information, namely, what interests and characteristics a certain group of people has?
For instance, the social group of "teachers" is X years old on average and their most popular interests are "children," "education," and so forth.
There're two groups of possible sources:
- Censuses and other government data (very limited and relatively easy to find)
- Social networks and their subservices, like AdWords, as well as general online data services
And I believe the latter needs a deeper exposition.