Word taxonomies for Facebook likes categories
I think total number of default categories in Facebook is somewhat static. There is around 140-160 categories. 

ref: https://stackoverflow.com/questions/4216648/facebook-pages-authoritative-list-of-categories/8576572#8576572 and http://www.marketinggum.com/types-of-facebook-pages-for-business/ 

You can cluster (manually) them in to 10-12 generic groups. 

eg: Sports Event, 
    Sports League, 
    Amateur sports team,
    Sports Venue,
    Athlete,
    Sports/Recreation/Activities etc
all belongs to Sports category. 

Similarly cluster and form generic groups.

And then you can assign a user to any of these generic group based on the like category.