Mark Oestreicher (Marko) is a veteran youth worker and former president of Youth Specialties. The author of dozens of books, including Youth Ministry 3.0 and Middle School Ministry, Marko is a sought after speaker, writer and consultant. Marko is a partner in The Youth Cartel, providing resources, training and coaching for church youth workers. Marko lives in San Diego with his wife Jeannie and two teenage children, Liesl and Max.