The document discusses two methods for categorizing audiences: Young and Rubicam's Four Consumers model and socio-economic class. Young and Rubicam divides people into four categories based on personality - Mainstreamers, Aspirers, Succeeders, and Reformers. The socio-economic model classifies people into six classes based on income - A through E. Both are useful for media targeting, but the socio-economic model is limited as it only considers income and not other factors like leisure activities.