Comment by vntok

Not necessarily.

You can make it collect personas from actual users who actually interact with you on social media, for example Facebook page fans or x.com followers.

If the models are built from those actual users and their public social graphs, that gives a lot of data points to the inference engine about their demographics as well as their interests.

No idea if the results are statistically relevant, but it might bring good enough results at a fraction of the time*cost of an actual study (that probably won't be statistically accurate either anyway).