These agencies are very focused on people. They look for recognizable types, who wish to feature in a commercial or on a billboard.
These agencies focus on youth, perfect sizes and looks. They do not represent the average young person, but rather the unique types that are unusual to find.
Film and television
If you aspire to become a fully-fledged actor, these agencies can be your stepping stone.
If you first want to discover your voice and fine-tune your timbre, take a look at this overview of voice coaches.