With Facebook Advertising, your audience can be targeted by a number of demographic and psychographic filters, including Age, Gender, Education, Location and Keywords.
The relevance of the advertising for the audience has taken a step up with the advent of real-time advertising. Facebook has been advertising to users based on the content of their posts and interactions on the platform for some time. They are now in the process of speeding this up to show relevant ads as the user interacts.This is similar to the way Google advertise to users of Gmail.
This should result in Facebook becoming a more effective advertising platform for business, particularly in the B2C space.