Mark Oestreicher (Marko) is a veteran youth worker and former president of Youth Specialties. The author of dozens of books, includingand Youth Ministry 3.0and andand Middle School Ministry, Marko is a sought after speaker, writer and consultant. and Marko leads The Youth Cartel, providing a variety of resources, coaching and consultation to youth workers, churches and ministries. Marko lives in San Diego with his wife Jeannie and two teenage children, Liesl and Max.and www.whyismarko.com.

SPANISH BIO: Mark Oestreicher con una vasta experiencia ministrando a jovenes, ha sido pastor en diversas iglesias y ha escrito mas de 20 libros para lideres y adolescentes. Hoy lidera Especialidades Juveniles en Estados Unidos y es considerado una autoridad en discipulado juvenil.