Mark Oestreicher (Marko) is a veteran youth worker and founding partner in The Youth Cartel, providing resources, training, and coaching for church youth workers. The author of dozens of books, including Youth Ministry 3.0, Marko is a sought-after speaker, writer, and consultant. Marko lives in San Diego with his wife, Jeannie, and two teenage children, Liesl and Max. Marko's blog: whyismarko.com.