[mainlime]

Behavioural targetting is slightly different. It works on the basis of building up a profile of a user based on their behaviour over time. Social networks on the other hand have access to user-submitted profiles.

As an example, with behavioural targetting you could take a guess at my age based on the sites I visit or which news stories are of interest to me. Using my social network profile saves all that guesswork because I've given you my date of birth.