I read Marketplace Christianity by Robert Fraser a while back. Bob was one of the leaders and teachers with Joseph Company (JOCO) with International House of Prayer when I was there in 2006 and 2008.
It was good to read an encouraging book that recognizes ministry is beyond the  'church' walls.

Favorite quotes: 

•  "97% of the pastoral, evangelistic, teaching, prophetic, and apostolic gifts are in Marketplace Christians and are to primarily opering in the marketplace. For Marketplace Christians, their field is their workplace and their flock is the people they work with."
• "Worship can be more than a song, It can be anything we do to 'love Him back." 
• "Spiritual greatness comes to those who simply pursue God earnestly: and pursuit of God begins and ends in prayer. "